(COVER)
2013 ‐ 2014

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1 - Scale Drawing, Angle Measure, Smart Labs
A01-02 -
B01-B16
40 min
6a - Spark timer notes for acceleration lab 6 XT1-XT3
6 - Acceleration with Car and Spark Timer
7 - Free Fall
8 - Projectile - ??? - TBD
12 - Centripetal Force
13 - Measuring Power
15 - Springs - Hooke's Law and Potential Energy
16 - Conservation of Momentum and Collisions
17 - Static Electricity Lab
21 - Simple Circuit Investigation Lab
24 - Pendulum Lab
26 - Speed of Sound
27 - Refraction with Laser
APPENDIX
29 - Newtons Laws Super Lab
G01-G09
80 min
H01-H06
40 min
80 min
M01-M06
80 min
N01-N05
40 min
P01-P05
80 min
Q01-Q05
40 min
R01-R04 80 min
V01-V04
80 min
Y01-Y06
80 min
AA1-AA2 40 min
AB1-AB6
80 min
AD1-AD2 40 min
AE1-AE5
80 min
TOC

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TOC

Step   3)   Choose   the   Insert   Tab
Step   1)   Type   in   your   data   without   units.
X   data   goes   in   column   A   and   Y   data   goes   in   column   B
Step   2)   Click   on   the   1 st
number   under   “A”   and   select   both   sets   of   data   (image   below   shows   selected   data)
Step   4)   Select   the   Scatter   type   Plot
Step   5)   Choose   the   plot   that   makes   points   only
A01

Step   6)   –   Graph   is   made   –   But   there   is   no   line   and   no   Title   or   axis   labels.
Change   the   Chart   Layout   by   clicking   the   first   layout   option   button
Titles   are   now   shown   on   the   chart   (as   seen   below)
Step   7)   Change   the   titles   and   axis   labels.
Double   click   the   title   you   want   to   change,   type   your   new   title,   hit   enter.
Be   sure   to   put   units   with   the   values   on   the   axis   and   make   the   chart   title   using   the   proper   Y   vs   X   notation.
Step   8)   Add   a   trendline   –   Right   click   any   one   of   the   data   points   and   choose   the   add   trendline   options.
When   the   format   trendline   option   box   opens,   move   it   to   the   side   so   you   can   see   your   graph   and   try   the   different   trendline   types   to   see   which   one   fits   your   data   the   best.
Sometimes   it   is   linear,   but   sometimes   a   curved   trendline   is   a   better   fit,   try   them   all   to   see   the   best   one.
Special   Note:    In   this   same   format   trendline   box   you   will   see   a   check   box   at   the   bottom   labeled   “Display   Equation   on   Chart”.
This   will   put   the   equation   of   the   line   of   your   graph   on   the   chart   and   can   be   useful   for   finding   slopes.
Step   9)   Printing   –   You   have   two   options   to   print.
If   you   click   on   the   chart   first,   and   then   hit   print,   the   chart   will   be   printed   on   a   whole   page.
Or   you   can   copy   the   chart   and   paste   it   into   Microsoft   Word   and   resize   it   as   part   of   another   document.
A02

______________________________________________________________________

Use of a protractor is rather simple. Be precise when using a protractor, make sure the base of the protractor lines up correctly with the line you are measuring the angle from and be sure the point where the lines intersect is directly in the center point of the protractor.
Often you have to extend the lines that make the angle you are measuring so that they will fall on the scale and you can accurately read where they line up.
Using a protractor is best learned by viewing examples. Let’s look at a few examples.
You want to measure the angle in the bottom left corner of this triangle. Place the protractor as shown below. Be sure that the point on the left corner of the triangle is in the center of the protractor and the bottom line of the triangle is exactly lined up on the 0 degree part of the protractor
Angle we are measuring Zero degree mark
Now all we do is look at the scale on the protractor to see where the line hits it. Note there are two scales on the protractor along the arc (one on the top and one underneath it). Looking at our scale, we see the angle is either
62
°
or 122
°
. Looking at the triangle we know the angle is less than 90 so we choose the 62
°
measure.
Another protractor example.

This line is on the 0 degree mark
You are measuring the angle between the two sides that intersect at the top
You look to see where the line intersects the scale.
Again you know the angle must be less than 90 degress.
So you choose the 66 degree measure.
66 degrees away from the 0 degree line
Sometimes you have to be creative to measure the angles of real life things because they can be a little awkward.
One trick you might try is to use a string in various ways so you can extend the side of something and get a decent angle measure. You could also try to trace a portion of something on paper, or fold the paper to imitate the angle that you want to measure.

What is a "Scale" Drawing?
A scale drawing is a miniature version of a real life thing that is drawn to proportion so that if you took the drawing and enlarged it to be the actual size, it would exactly resemble the real life object. When making a scale drawing be sure to use a ruler and a protractor. Measure the lines you are going to draw, make them straight and measure angles properly with a protractor if needed.
Making your own Scale Drawing
The distance from NY to CA is approximately 3000 miles. If you wanted to make a scale drawing of the road on your paper, you can't make a line that is 3000 miles long. You have to establish a scale.
When making a scale drawing, ALWAYS USE THE CENTIMETERS PART OF YOUR RULER (cm). Each centimeter is broken into 10 equal divisions and is easier to use.
The first part of making a scale drawing is choosing a scale. You should choose your scale so that your drawing is not too small and not too large. It takes some practice and experience to choose a scale but a little trial and error will give you an adequate drawing. You can often look at the largest dimension you need to draw to determine what scale you should use.
In the example above with the road from NY to CA, a scale of 1 cm = 500 mi would be appropriate. With this scale, your road would be 6 cm long.
Your scale will always be of the form [ 1 cm = X ] which states that every 1 cm you draw on paper represents
X units of the real life dimension

You want to draw a side view of a house on a piece of paper to scale. You measure the house and find out that it is 45 feet long and 21 feet high.
We have to draw two lines to make the rectangle, which will be the house. I will chose a scale of [1 cm = 5 ft ]
The scale factor we just found is actually like a new conversion factor. It is telling us that (1 cm = 5 ft)
(its sort of like the conversion factors we used before such as (1 ft = 12 in), except this one is special only for this example). We can use it the same way we used our other conversion factors in order to determine how long we should actually draw each line on the paper.
We have to draw two lines, one that will represent the length of 45 ft and the other for the height of 21 ft. Lets determine how long we should draw them on the page.
⎜
= 9 cm
= 4.2 cm
What we did here was use our scale factor (1 cm / 5 ft) to convert our real life house measurements to values we could draw on paper. The first conversion showed us that in order to make a line that would represent 45 ft .. we would have to draw it 9 cm long. This makes sense, think about it: if every 1 cm we draw represents 5 ft in real life .. then a 9 cm line ( 9x5 = 45 ) would be like a
45 ft line in real life, it works out.
Now that we have the paper dimensions, all we have to do is use a ruler to
So we need to draw the length of the house 9 cm long and the height of the house 4.2 cm high. Be sure to note your scale on your drawing.
The House That Love Built
Scale
[ 1cm = 5 ft ]
(If you use a ruler and measure the house, you will see that it is drawn to scale, the man is sort of big though)

Science labs are based on real life data. The results and calculations made with lab data should make sense.
Labs are usually based on real life principles that work and when doing a lab write-up you should use your head and make sure your data is good and what you are doing makes sense.
Rule #1 - Have an idea of what you are doing. If you are warming an object up, and you are taking temperature readings that are decreasing, then chances are something is wrong. If you are taking time readings and find that it takes 30 seconds for something to fall off the desk, something is wrong. If repeating the same task over and over and 1 of the results is very different from the rest, something is most likely wrong with that result. Keep these things in mind, and ask your teacher if you notice one of these abnormalities … as the year goes on, you will be able to handle these problems yourself.
Samples
The following data was recorded in an experiment to find the velocity of a car. We observed visually in the experiment that the car was constantly speeding up. See if you can find any errors that might exist in our recorded data. Then read below to see what the errors actually are.
Distance of Car Time trial #1
5 m
15 m
20 m
0.25 sec
0.40 sec
0.50 sec
Time trial #2
0.027 sec
0.43 sec
0.51 sec
0.60 sec
Time trial #3
0.22 sec
0.42 sec
0.89 sec
0.57 sec
Average Time
0.16 sec
1.25 sec
1.5 sec
0.59 sec
Speed (m/s)
31.25
12.00
13.33
423.7 m/s 25 m 0.58 sec
Problems with this data
First of all we should notice the speed. In the experiment we noticed the car was speeding up, but this data shows the car doing weird things, getting slower and such .. it doesn’t make sense. Maybe something is wrong with our calculations, or maybe something is wrong with the data.
First row - notice time trial #2 compared to the others … it is much to small, it was most likely an error and should be thrown out or redone if caught while doing the experiment.
Second row - the speed goes down so that doesn’t make sense - maybe our math is wrong. Look at the average time. If we know something about averages we know this cant be correct and is a math error. If we look at the data we see that the times don’t change very much at one given distance ... therefore, the average should be close to any of the time values in that row. The three times 0.40, 0.43 and 0.42 are so close to each other that the average would be close to them as well. We therefore know that the average time of 1.25 seconds is a mistake. The person forgot to divide by three when they did the average formula.
Third row - well the speed has increased a little from last time, which is ok, but its still less than the original (there was a mistake with the original speed to begin with so that might be the problem, but lets check it out anyway).
Look at the times in row three ... 0.50, 0.51, 0.89 ... the last time seems very different from the first two and is probably an error. It should be thrown out for the analysis or redone if caught before the lab was over
Last row - the speed calculated in the last row seems high, that car would be moving at about 900 miles per hour.
Rule #2 - Data is not perfect, allow some discrepancy to what you think should occur, but be aware when there is a large amount of error, something might be wrong.
Rule #3 - When comparing multiple values, if you notice that most of your values generally increase, then that is probably a trend. If the values are more or less the same but go up and down a little bit each time, then chances are those values should all be the same but experimental error makes them all a little different

Physics Labs also incorporate the use of graphs to interpret and display data. There are a number of important facts to know when making graphs.
1.) Your graph should always be labeled with a title, axis labels, and units on the axis labels.
Distance vs Tim e
35
30
25
20
15
10
5
0
0 1 2 3 4 5 6
Tim e (sec)
2.) Your graph should always have a best fit line drawn on it. (The graph shown above would loose points for lack of a best fit line). To determine the best type of fit, simply look at your data points to see how the trend is.
In the above graph, we can see that it is clearly indicating a curve. Other data sets will indicate straight line best fits. Never simply connect all data points.
Distance vs Tim e
35
30
25
20 y = e 0.6931x
15
10
5
0
0 1 2 3 4 5 6
Tim e (sec)
3.) If using Microsoft excel to make graphs, the only type of graph you should ever make is XY scatter, and you use the one that makes points only. Then, after the graph is made, you right click one of the data points and choose add trendline. Try out the difference trendlines to see which one fits best.
4.) Which values to place on the x and y axis is usually determined for you in a Physics lab and should not be done simply by your choice. This is a very important point to remember: Graph types are always stated in
the form Y vs. X, and the Y axis value is always listed first with x axis value following it. For example,

Distance vs. Time, means Distance is the y axis value and time is the x axis values. A graph of Density vs. Mass would indicate Density is on the y axis. In the rare case that you have to choose x and y axis values, the independent variable goes on the x axis. This means that the variable that is unaffected by the other quantity is the one that you put on the x axis.
5.) Lab data is not perfect. Most of the time, your graphs will not form perfect curves or perfect lines, that is the reason for the trendline … it draws a best fit of the data. Occasionally, an error on your part will result in a data point that skews the graph and changes the trendline. You should be able to notice this error and in this case you should eliminate the bad data point.
Example.
Distance vs Tim e
25
20
15
10
5
0
0 1 2 3 4 5 6
Tim e (sec)
Clearly this data is indicating and upwards sloping trend, and the trendline does show that, however, it is being skewed by the data point at 3 seconds which is clearly a mistake. The point should be removed and you should note that you did that. The corrected graph is shown below.
Distance vs Tim e
6
4
2
0
0
14
12
10
8
1 2 3
Tim e (sec)
4 5 6

An experiment is being conducted in three identical jars full of water. They have three candles held underneath them to heat the water. The temperature is recorded every minute.
ROW #
1
2
3
4
5
6
7
Time
1 min
2 min
3 min
4 min
5 min
6 min
7 min
Jar 1
Temperature
10.06
°
C
13.71
°
C
20.25
°
C
16.20
°
C
24.40
°
C
28.00
°
C
46.60
°
C
Jar 2
Temperature
10.13
°
C
13.70
°
C
20.50
°
C
16.05
°
C
24.35
°
C
27.98
°
C
46.35
°
C
Jar 3
Temperature
10.00
°
C
13.71
°
C
20.55
°
C
16.15
°
C
24.42
°
C
24.89
°
C
46.50
°
C
Average temperature
14.56
°
C
13.71
°
C
20.43
°
C
16.13
°
C
24.39
°
C
26.96
°
C
46.48
°
C
There are not necessarily errors in every row, but there are 4 total errors in the data. (if there is a single error that in turn causes other errors, that should be considered only one error total)
Only 1 error is a calculation error.
Other errors are based on the experiment as a whole and what you would expect the results to look like as it progressed. (read the description of what is actually being done here)

2.)
The
following data is from an experiment measuring pressure in Pascals and volume in cubic meters
Volume (m
3
) Pressure (Pa)
1 100
2.5 40
4 25
5.75 17.4
8 12.5
(a) Based on your knowledge from chemistry and gas laws, predict what the shape of the graph Pressure vs.
Volume should look like and draw it below. Be sure to label each axis with units.
(b) Using the real lab data, create a graph of Pressure vs. Volume by hand. Again label everything. Put a best fit line or curve on the graph.
(c) Your predicted graph and your actual graph might look very different from each other. This relationship is an inverse relationship. The actual graph you made should be a curve and is the correct look of an inverse graph.
Some students believe an inverse looks like a straight line sloping downward; this is incorrect and will never occur in a physics lab or test. It is very important to note that inverse graphs are always like the graph you plotted in the grid.

3.) The following data is from an experiment measuring Force in newtons and mass in kilograms.
Mass (kg) Force (N)
1 10
2 23
3 29
4 43
5 50
6 95
Create a graph of Force vs. Mass by hand and draw a best fit line. Be sure to state any corrections here
that you need to make for lab data errors, and make those corrections.

1 - Measure all angles in this shape. Be as accurate as possible, you will only be given a 1 degree margin or error.
2 - Measure the angles between the lines drawn below (you will need to extend the lines with a ruler in order to see where they fall on the scale on your protractor, show your line extensions).
3 - Draw two lines that are separated by an angle of 35 degrees.

(b)
4 - Make a scale drawing of a Boat that is 25 ft long and has a sail that rises 40 ft into the air. Be sure to show the conversions from real life measures to paper measures .. follow the steps below.
Choose a scale for your boat (a)
State your scale factor here [ ]
Use your scale factor to convert the real life boat dimensions into paper dimensions.
Length (25 ft)
⎠
=
Height (40 ft)
⎠
=
Draw your scale drawing here (draw the boat). State your scale next to the drawing .
Be sure to use a Ruler to draw straight lines properly measured.

… continued
(c) - Measure a TV in inches. Write down what the measurements of the TV are. Then follow the same steps as shown above to make a scale drawing of your TV.

5 - Use two of your fingers (not your thumb) to trace a V shape on the paper. When you trace the shape, it will be sort of a U shape, use a ruler to turn it into a V shape. Now measure this angle
6 - Measure the dimensions of the top of your kitchen table in inches (be sure to use the inches side of a ruler) Record these dimensions below (if your table is round, then just pretend it is a rectangle and measure the longest center parts of the table, then draw it rectangular when you are done). If you don’t have a kitchen table for some weird reason, then use a different table in the house.
Length ____________
Width ____________
7 - Measure parts of your body in inches
Length of your head
Length of your arm
Length of your leg
Length from your chin to waist
_____________
_____________
_____________
_____________

8 - Make scale drawings of the table and your body.
Be sure to indicate your scale next to your drawing. Draw your body as a stick figure. Separate each arm 60
° from your torso and separate your legs by 30
°
from each other

Introduction to Spark Timer
A spark timer is used to make accurate time and distance measurements for moving objects. To put it simply, a spark timer is like a high tech stopwatch. It is basically a small box through which a piece of special tape is pulled through. Inside this box, a spark is made and repeats in a known amount of time. When the tape is pulled through the box, sparks marks are made on the tape.
Sparks made here
Tape pulled through
Since we know how often a spark is made, we can count the number of marks on the tape to see how long it took the tape to move through. A finished tape would look something like this.
● ● ● ● ● ● ● ● ●
Using the Timer
As seen above, the timer will make a series of dots and therefore also a series of “spacings” or gaps between dots. It is these spacings that we want to focus on. The timer is set to produce these spacings at a known time interval. The timer can be set at either 1/60 of a second (60 Hz) or 1/10 of a second (10 Hz). When set at 1/60 of a second, this means that it takes 0.0167 seconds (1/60) to make a space. A setting of 1/10 would then mean each space is made in 0.10 seconds.
We can easily measure a spacing with a ruler to find the distance. The time for the spacing is also known (1/60 or 1/10 sec per space depending on how the timer is set). We can therefore use this data to determine the speed at a given spacing by finding distance over time.
Sample tape analysis: The spark timer is set at 1/60 and a motorized car pulls it through. The tape is shown below.
● ● ● ● ● ● ● ● ●
Visual Analysis: Since the dots get farther and farther apart in the beginning, we can see that the car must be speeding up Î logically, if each dot is made in the same amount of time and the spacing between them is getting larger, the car must go faster for this to happen. In the second half of the tape, the dot spacing is constant and therefore we can conclude the car was moving at a steady rate (constant speed)
Note: The spacing between each dot is what we are measuring here, not the dot itself. Therefore, we want to count the # of dot spacings to determine the amount of time for a given distance rather than counting the # of dots by themselves.

● ● ● ● ● ●
In itial and Final (Instantaneous) speed of car:
● ● ●
Instantaneous speeds can be assumed to be average speeds over very short time intervals.
The initial speed of the car will simply be the speed of the first spacing which can easily be found by using the distance and time of this spacing. Likewise, the final speed will be determined using the last spacing.
For the sample tape above:
The first spacing takes 1/60 s ec to make and measures 0.5 cm (.005 m).
This gives a speed of (v = d/t = 0.005 m / (1/60) sec) = 0.3 m/s
The last spacing takes 1/60 sec to make and measures 3.5 cm (.035 m)
This gives a speed of (v = d/t = 0.035 m / (1/60) sec) = 2.1 m/s
Average Velocity of the car : The average velocity of the car is defined by the total distance traveled / total time.
Using the tape, we measure the distance from the first dot to the last dot with the ruler.
Then we can count the total number of spacings and add up to get the total time
NOTE: The time used here is not 1/60 of a second, rather it is the total time.
Measured Distance = 15.4 cm convert to m Î total distance = 0.154 m
Total # of dot spacings = 8 x (1/60 sec) per spacing Î total time = 0.133 sec
A vg Speed
= dist / time
= 1.16 m/s

A toy car has a spark timer tape attached to it and moves down a track. The timer is set to the 1/10 setting.
● ● ● ● ● ● ● ● ● ●
Visually inspect the tape above and qualitatively (no numbers) explain what the tape tells you about the motion of the car. Explain your reasoning.
Calculate the average velocity of the car, the initial instantaneous velocity of the car, and the maximum instantaneous velocity. (show all work with all equations and units)

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spark timer timer tape stop watch cart old books and/or bricks
ramp masking tape
CATCH THE CAR
WHEN IT
REACHES THE
BOTTOM.
_____1.
_____2.
_____3.
_____4.
_____5.
_____6.
_____7.
Set up the apparatus shown above. DO NOT tape the timer tape to the wheel. Place the spark timer directly on the ramp behind the car. Start with a ramp height of about 50 cm
Rip off about 40 cm of spark tape and attach it to the car so that the outside part of tape faces up.
Set the timer to 1/60 (60 Hz),
Put the car at the top of the ramp, feed the spark tape in the timer and attach it to the car. Hold a meterstick across the track in front of the car. Turn on the timer and smoothly remove the meterstick to release the cart while your lab partner stands ready to catch it at the end of the ramp. DO NOT USE THE STOPWATCH until step 13.
Visually inspect the tape to make sure it makes sense as sometimes the timer can skip a dot … if you see something strange, ask your teacher to inspect it)
Switch places and repeat so that each person has his/her own tape.
Draw a line through the first distinguishable dot at the beginning of the tape and label this “start”.
Draw a line through a dot towards the end of the tape and label this “end”. Be sure that the start and end marks represents points where the car was moving on the ramp unhindered. Your tape should look something like the picture below.
START END
_____8.
_____9.
Measure the distance between the start and end lines and make a note of it.
Start-end distance ________________
Get an average value of your whole lab group
Average distance ________________
Cut the tape at appropriate locations and fix it to the “tape timer collection sheet” provided (keep the tape in order when taping it to the sheet).

_____10.
_____11.
_____12.
Return to the lab apparatus and remove the spark timer from the experiment.
_____13.
_____14.
Put the car on the top of the ramp in the same spot that it started when using the timer tape.
Put a piece of masking tape on the side of the ramp lined up with the front wheel of the car.
DO NOT PUT TAPE DIRECTLY ON THE FLAT RAMP SURFACE Using the average distance recorded in step 8, measure down the length of the ramp that distance and put a second piece of tape on the side of the ramp to mark the end of that distance.
Release the car down the ramp and use the stopwatch to record the time it takes to cover the distance between tapes (record the time from when the car starts to when the front wheel hits the second tape)
Repeat the drop two more times to have a total of three trials. Measure the time with the stopwatch each time and record it.

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PART A.) Timer Tape Measurements (ONLY USE THE TIMER TAPE FOR THIS PART)
1.) Use your timer tape to calculate the average velocity of the car, in m/s, over the total distance. Show and explain work with formulas and units.
2.) Use your timer tape to calculate the instantaneous initial and final velocity of the car (this is the same as you did in the “spark timer” lab) Show and explain work with formulas and units.
3.) Use the information in part 2 above to calculate the average velocity, in m/s: v = v i
+ v f
4.) Which of the two average velocity calculations performed do you think is more accurate, explain. (Don’t make a silly statement like ‘the formula has less variable so less error’, that makes no sense. One method is more accurate based on how it is determined and what goes into it, not based on possibility for mistakes)

5.) Determine a percent error between the two calculated average velocities and use the value you consider more accurate as the accepted value. Show formula and work with units.
6.) Using only the velocities from part 2 (vi and vf) on the previous page, and the total time of movement, determine the acceleration of the car, show all work with formulas and units.
PART B.) Stopwatch Measurements – (use the stopwatch times as well as the distance on the ramp for this part)
1.) Find an average value of the three times recorded using the stopwatch, show work.
2.) Assume the car started from rest (v i
= 0) and use the distance and time values recorded in the stopwatch part of the lab to determine the acceleration of the car. This is just like a normal physics problem from class. List all the known variables, pick an equation, plug in and solve.

3.) In part A step 6 and in part B step 2 you calculated two different accelerations, which do you think is more accurate, explain your reasoning
4.) Determine a percent error between the two calculated accelerations and use the value you consider more accurate as the accepted value. Show formula and work with units.
C.) Graphs
1.) Using a ruler, measure the distance on your spark tape for the dot intervals indicated in the chart and fill in the chart. Note that the INTERVAL NUMBER: 1,2,3 … does not represent each spacing since we are starting from dot one each time. The time and distance should be getting significantly larger for each interval.
2.) Each dot spacing on your tape represents a given amount of time based on what the spark timer is set to, as we learned in the spark timer lab. Use this fact to calculate the times for the intervals shown in the chart below.
Be careful because each interval has a different number of spacings. The first interval is only 1 dot spacing (dot
1-2) while the second interval is 3 dot spacings (1-2, 2-3, 3-4)
Explain how the time is calculated.
Interval Time (s) Distance (m)
(1) Dot 1 Æ Dot 2
(2) Dot 1 Æ Dot 4
(4) 1 Æ 8
2.) Using a computer program, make a graph of distance vs. time and attach it to this report.
(The terminology __ vs. __ tells you which value to put on the x and y axis)

1.) List reasons for error in any part of this experiment. Do Not simply write “human error” or “miscalculations” or “rounding”; those are not reasons for error. Reasons for error can include human factors, but you should specifically state what they are rather than writing ‘human error’. Furthermore, errors are not mistakes or things you could correct, rather they are uncontrollable and could be there no matter how many times the experiment is conducted.
2.) The graph you created in this lab is a “d vs. t” motion curve. Based on the principles of motion curves learned in class, what does the shape of the graph suggest about the motion of the cart. Explain your reasoning.
DO NOT SIMPLY SAY ‘as time increases distance increases’, rather analyze this graph as though it was a question from a homework assignment on motion curves asking you to interpret what the graph tells you about what the car is doing.
3.) In part B of the lab you calculated the acceleration of the car with the stopwatch time.
List that acceleration value here ____________________
(The following questions are just like basic kinematics word problems as we did in class, simply label all info, pick a formula and solve)
(a) Using the value of acceleration written above, and the fact that the car started from rest, determine how fast
( in m/s) the car would be moving if it accelerated for 10 seconds, show formula and work with units.
(b) Using this same information, how long (in meters) would the ramp have to be in order to allow the car to roll for 10 seconds, show formula and work with units.

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Name: _________________________
PART A – Measuring your reaction time.
_____ 1.) Hold a ruler vertically and have your lab partner put their index finger and thumb at the 50 cm mark ready to catch the ruler once it drops. Drop the ruler so it falls straight down and let your partner catch it with the two fingers.
_ ____ 2 .) Record the distance th e ruler fell.
_____ 3.) Switch partners and get results for t he whole group.
_____ 4.) Record everyone’s results and calculate their reaction ti mes, show calculations. Tell the winner that they are the coolest for being so quick.
Reaction
Time
Do not calculate the times now. Do this once the lab is finished.
Show a sample calculation of how you did your work for one person. Remember, this is a simple free fall problem that star from rest. Just like a problem in class, write down all known variables, pick an equation and solve for the unknown. ts

PART B – Acceleration of Gravity.
Description of Task - Use the spark timer, tape, and weight to find an experimental value of the acceleration due to gravity. Use about 50 cm of spark timer tape.
Procedure
_____ 1.) Set the spark timer to 60 Hz. With this setting, each dot spacing gives you 1/60 of a second.
_____ 2.) Place the spark timer so that it rests horizontally on the edge of the table and overhangs slightly
_____ 3. Attach a 50 g weight to approximately 50 cm of timer tape (does not have to be exact), and feed it into the spark timer with the proper side facing up.
_____ 4.) Turn on the timer, drop the weight on a book so that it does not mark the floor, then turn off timer.
_____ 5.) Visually inspect the tape to make sure it makes sense as sometimes the timer can skip a dot … if you see something strange, ask your teacher to inspect it.
_____ 6.) Get one tape for each member in the group. Make sure the dots that you are going to use represent times when the mass was freely falling.
_____ 7.) Cut the tape at appropriate locations and attach it to the tape timer collection sheet.
-

– be sure to organize your analysis so that it is clear and easy to follow
Part A – Reaction Time.
Return to page 1 and calculate reaction times. Show one sample calculation of how you arrived at your results.
Part B – Finding “g”
1.) DO NOT USE THE FIRST FOUR SETS OF DOTS on the timer tape. Draw a vertical line on the fifth dot that you will use and mark it “start”. Also draw a line at the end of the tape on your last dot and mark it “end”.
2.) Measure and record the total distance traveled from “start” to “end” _________________________
3.) Velocity Calculations
Complete the values in the table below, put units in the top row with the labels. (Be sure to show sample calculations below the table). Each single interval has the same time, but the elapsed time is the total sum of intervals up to the interval you are looking at. USE METERS AND SECONDS, NOT CENTIMETERS. DO NOT PUT
FRACTIONS IN YOUR TABLE, USE DECIMAL NUMBERS.
Dot Spacing Distance of
Interval
Time of
Interval
Instantaneous
Velocity
Total elapsed time since start
1 (dot 1-2)
2 (dot 2-3)
3 (dot 3-4)
Continue for
all spacings
4
(if you run out of rows, you can leave off the remaining dots)
Sample
Calculation:

4.) Acceleration of gravity “g”
(a) Make a FULL PAGE graph of Instantaneous Velocity vs Total Time (remember what the “vs.” means). Be sure that the time is the total elapsed time from the start to the point you are looking at and NOT the time only for that interval you are in. Add a best fit line or curve to the graph (use excel’s trendline feature). If your best fit is a curve (it shouldn’t be), add that trendline, however we also want to add a linear trendline as well to be used to get an average value for the acceleration. If you have a curve, this linear line should be added by hand as a dotted line.
(b) Using only the “v vs t” graph, determine the acceleration of the falling object using the linear trendline. Do not use physics formulas to calculate g … we have made a V-T motion graph and we can use this to find the acceleration just as you would on a motion curve homework assignment. DO NOT PICK A SINGLE POINT and plug it into the acceleration equation. CLEARLY SHOW YOUR WORK AND EXPLAIN HOW YOU ARE PERFORMING
THESE CALCULATIONS OR HOW YOU GET YOUR ANSWER.
This value of g, acceleration due to gravity, will serve as our experimental value for “g”.
(c) Using only the V vs T motion graph, find the total distance traveled from the start to end. Explain how you find it and then do it. Again use only the whole graph itself and the principles of motion curves to find the distance, DO NOT PICK A POINT from the graph and plug into acceleration equations. Be careful when you do this part, most students make a careless mistake getting the correct value for this.

1.) List reasons for error in any part of this experiment. Do Not simply write “human error” or “miscalculations” or “rounding”; those are not reasons for error. Reasons for error can include human factors, but you should specifically state what they are rather than writing ‘human error’. Furthermore, errors are not mistakes or things you could correct, rather they are uncontrollable and could be there no matter how many times the experiment is conducted.
2.) Find the percent error of the acceleration you calculated vs. the known accepted value of g. Show work.
3.) In part 2 of the Analysis, you measured the total distance traveled by the weight. In part 4 (c) of the Analysis you used a motion graph to calculate the total distance traveled by the weight. Find the % error of these two calculations and use the measured value as the accepted value.
4.) You created a “v vs t” motion graph in this lab. What does the shape of this graph suggest about the acceleration and velocity of the falling object? Describe the behavior and describe how you used the graph to get that information. (Answer as if you were given these motion graphs on a quiz and were asked to describe the motion of the object).

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- Analysis of the circular motion of a swinging stopper will provide insight into the causes of centripetal force and develop relationships between speed, radius and centripetal force.

1. Measure the mass of the rubber stopper using a scale and record in the attached data table.
2. Attach 200 g of mass to the bottom of the string that passes through the tube. Refer to the diagram to understand how to measure the radius. Before swinging the stopper, measure the radius so that it will be somewhere between 50-60 cm and record this value.
RADIUS USED: _______
3. Put an alligator clip on the string just underneath the bottom of the tube and wrap the string once around one side of the clip teeth so that the clip will not slide if pushed (see diagram).
PART 1 - Changing Mass - READ UP TO STEP 5, BEFORE BEGINNING
Practice swinging
Hold the apparatus as shown in the picture and use your free hand to hold the weight hanging below the tube.
Begin swinging in short horizontal circles to make the stopper go in a horizontal circle around your head.
Place alligator clip
Once you get it moving, slowly release the weight in your hand until it hangs freely.
Vary the speed at which you swing the stopper until you can get the alligator clip to be just below the bottom of the tube without it touching the tube .
Keep the swing constant so that the alligator clip remains in place and does not move up or down.
4. In this part of the lab we will be varying the mass hanging on the rope. Choose a starting mass of either 100 or 200 grams. If you are able to swing the mass successfully with the 100 gram weight, then start with that mass, however, if the stopper is too heavy and it is difficult to swing with such a small weight then start with the 200 gram mass.
5. We will now take data while spinning the stopper, please read the recommendations that follow , don’t be lazy. Sometimes the stopper will be swinging quickly so be careful when you are counting the revolutions.
The person swinging the stopper usually has the best idea about the numbers of revolutions and you can even hear the swirling noise of the stopper to help you count. The person doing the swinging can begin counting aloud from 1 – 27, and the person timing can start the stopwatch when they hear 5, and then stop at
25 so there will be a more accurate result of the beginning and end of the 20 revolutions. Use whatever method is best for your lab group for counting and timing. Record your data in the attached data table.
Make sure the stopper is spinning at a constant rate in a horizontal circle and the alligator clip remains at the same spot (just below the tube but not touching), and record the amount of time required to make 20 revolutions of the stopper.
6. Repeat step 5 one more time so that you will have two trials total.
7. Add an additional 100 g of mass hanging to string to increase the total mass
Repeat the two swing trials again and record your times on the data table.
8. Add another 100 g of mass (200 g total additional added)
Repeat the two swing trials again and record your times on the data table.
9. Add a final additional 100g of mass (300 g total additional added)
Repeat the two swing trials again and record your times on the data table.

PART 2 - Changing Radius
1. Copy the data from the first row of “part 1” table and make an exact copy in the first row of “part 2” data table.
2. For rows 2-4 in the part 2 table, use the initial amount of hanging mass on the string as you did in part 1, and do not add or remove mass for any part. In this part of the lab we will vary the radius at which the stopper spins around.
3. Move the alligator clip 10 cm up or down the rope from its current location (this will make a different radius when the string is swung). Again wrap the string around one of the alligator teeth so that it will not slide if pushed.
Record the value of the new radius in your table.
4. Repeat the experiment as conducted before so that the clip is just barely below the glass tube and does not move. Get the time to make 20 revolutions. Repeat this step 1 more times for a total of 2 trials.
3. Move the alligator clip to another different location (10 cm different than other trials) and record it. Measure and record the time for 20 revolutions. Repeat this step 1 more time for a total of 2 trials.
4. Again, move the alligator to a new location (10 cm different from other trials) and record the time for 20 revolutions. Repeat this step 1 more time for a total of 2 trials.
------------------------------------ END OF EXPERIMENT -------------------------------------------------

A common mistake in this lab is misunderstanding which mass to use . There are two masses, the hanging mass (the one hanging below the circle attached to the string) and the mass of the stopper. Each mass is used for a different thing in the analysis. Keep in mind that the stopper is the thing that is going in the circle, so when using circular motion analysis it is the stopper mass that is being accelerated.
Complete the calculations on the data worksheet. Read the directions below to assist you.
(a) Hanging mass weight and Fc
Why does the spinning stopper maintain its circular motion in this lab? The stopper goes in a circle because a centripetal force allows it to happen. A centripetal force is always provided by something. In this case the string tension provides the centripetal force. However, if there was no mass attached to the string then the stopper would just fly away and the hanging mass creates the tension which provides the centripetal force, so in essence the weight of the hanging mass provides the centripetal force acting on the stopper. (note, if you are one of the few people that actually read directions, this paragraph is the basis for the answer to one of the questions, congratulations.)
This important relationship directly gives us F c
. Now that we know the F c
we can calculate other values.
(b) Speed (V)
We are going to find the speed of the stopper with two methods and compare the results. For the purposes of percent error, we will assume that Method 1 is the experimental value and Method 2 is the actual value.
Method 1 (experimental V) - find the speed using distance and time.
In lab we found the time needed for 20 revolutions which we can easily use to find the Period. (Period =time needed to make 1 revolution)
We also know the distance traveled in 1 revolution. The stopper swings in a circular path and we know the radius of this circle. The distance traveled in 1 revolution around a circle is the circles circumference C = 2
π
r
With the distance and time traveled, we can find the speed of the stopper in the circle. This is method 1.
Method 2 (actual V) - find speed using the known centripetal force
In accordance with the discussion in part (a) of this analysis we know the centripetal force on the stopper. We also know the mass of the stopper and radius of the swing. Given the formula for centripetal force:
F net(c)
= m a c
2
net(c)
=
We can see that the only unknown left in the equation is v so we can rearrange the equation to solve for v.
Read the note at the top of this page again to be sure to use the correct values.
(c) Find the percent error for the two methods of v
1. Make a graph of centripetal force vs. speed(method 1) for part 1 of the lab ( y vs. x )
2. Make a graph of speed(method 1) vs. radius for part 2 of the lab ( y vs. x )

ALL MASSES SHOULD BE CONVERTED TO kg
Part 1 - Constant Radius, Changing Mass
Hanging
Mass (kg)
Weight of
Hanging mass (N)
Radius
(m)
Mass of
Stopper
(kg) shaded columns = data to record during lab
Time for 20 revs
(s) Average
Trial 1 Trial 2
Time for 20 revs (s)
Time for 1 rev (s)
F c
(N)
V
Method 1
(m/s)
V
Method 2
(m/s)
% error
V
Sample Calculations:
Part 2 - Constant Mass, Changing Radius
Hanging
Mass (kg)
Weight of
Hanging mass (N)
Radius
(m)
Mass of
Stopper
(kg)
Time for 20 revs
(s) Average
Trial 1 Trial 2
Time for 20 revs (s)
Time for 1 rev (s)
F c
(N)
V
Method 1
(m/s)
V
Method 2
(m/s)
% error
V

1.) List reasons for error in any part of this experiment. Do Not simply write “human error” or “miscalculations” or
“rounding”; those are not reasons for error. Reasons for error can include human factors, but you should specifically state what they are rather than writing ‘human error’. Furthermore, errors are not mistakes or things you could correct, rather they are uncontrollable and could be there no matter how many times the experiment is conducted.
2.) Explain how you found the F c
acting on the stopper and why this is the correct way of calculating it.
3.) What does graph 1 suggest about the relationship between speed and centripetal force? Does this make sense, explain? (you must refer to a physics formula)
4.) What does graph 2 suggest about the relationship between speed and radius? Does this make sense, explain? (you must refer to a physics formula)
5.) Which method of solving for v do you think is more accurate and why (Don’t refer to one formula being harder than the other, accuracy should be based on the values used to find answer, not the actual formulas themselves)

The purpose of the following exercise is to measure the power you develop while first walking, and second, running up a flight of stairs.
Power (P) = Work (W)/time (t) and W= F•d, where in the case of doing work against gravity the force used in doing the work must be at least equal to the weight of what is being lifted
1.) Using the available scale, determine your weight
2.) Now, using a stopwatch, walk up a flight of stairs and record the time it takes. Do two trials.
3.) Using a meter stick, measure the total vertical distance you walked.
4.) Repeat the same procedure, but run instead of walking. Do two trials
5.) Record values for other members in the group.
Calculations:
Separate your analysis into two separate sections, one walking section and one running section. For each section calculate the following:
1) Convert weights in lbs to kg (1 kg = 2.2 lbs)
2) Average the two time trials for each person
3) Calculate the work done by each person
4) Calculate the power of each person in Watts
5) Convert the power to kilowatts.
6) Find averages

Walking
Person
Time 1
(sec)
Time 2
(sec)
Avg
Time
(sec)
Average
Sample Calculations:
Running
Person
Time 1
(sec)
Time 2
(sec)
Avg
Time
(sec)
Averages
Weight
(lbs)
Mass
(kg)
Weight
(lbs)
Mass
(kg)
Weight
(N)
Distance
(m)
Work
(J)
Weight
(N)
Distance
(m)
Work
(J)
Power
(W)
Power
(kW)
Power
(W)
Power
(kW)

1. How does the power you develop change when you run up the steps instead of walking, explain why your answer is the way it is.
2. Examine other people’s data. What type of person seems to develop the greatest power? Did anyone reach
1 horsepower (look up the conversion if you don’t know it)
3500 Kcal is equivalent to 1.47x10
7 J
3500 Kcal expended results in 1 lb (fat) burned
1.47x10
7
or
J expended results in 1 lb (fat) burned
3500 Kcal = 1.47x10
1 lb = 3500 Kcal
1 lb = 1.47x10
7 J
7 J
Your answers must be given by actually showing conversions from one value for another by using the above factors and the factor label method
Recall from beginning of year, to convert ft to cm
(
)
= 3048 in
So when answering the questions you should use a similar method only with the new factors and factors you can make from your data table.
3. Determine how many times the average person would have to run up the steps to lose 1 pound of body fat.
The factors have been setup for you. Use your data table and the proper factors from above to fill in and get the final answer of stair runs per lb.
(
(
________
________
J lb )
)
x
( 1 stair flight run )
=
( ________ J )

3500 Kcal = 1.47x10
1 lb = 3500 Kcal
1 lb = 1.47x10
7
7 J
J
4. How many Kilocalories do you estimate the average person expends in one hour of stair running? (The question is asking you to convert 1 hr of stair runs into kilocalories of energy
(
(
_____
_____ runs sec
)
)
x
( ____ sec )
x
( ____ hr ) (
( ____
____
J ) run )
x
( ____ Kcal )
( ____ J ) cancel the units above in the proper manner
Answer with unit
Kcal burned per 1 hr of stair running _____________
5. Use the answer to question #4, and the same factor method, determine how much body fat is burned in 1 hour of stair climbing.

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In this lab you will investigate the force and stretch in a variety of springs as well as investigate energy.
Part 1 – Collecting data to determine the spring constant (see included table within lab)
For each spring and rubber band provided, (data table attached)
Hang the spring on a clamp and measure the initial length of the spring. (note: for the rubber band you will have to put a small insignificant amount of weight on it to get the relaxed length, you can ignore this tiny amount of weight in the analysis)
Attach different masses to the spring and measure the final length of the stretched spring. Each trial should add at least 100 g of mass (for rubber band: 200g additions will most likely be needed). The amount of mass added to the spring should be enough so that the stretch is noticeably measurable and each trial is noticeably different.
Calculate the change in length for each mass.
Use at least 5 different masses for a given spring and repeat the process for each spring or elastic band that is provided. You DO NOT, and probably SHOULD NOT use the same 5 masses for each spring. Make a separate table of information for each spring.

Part 2 – Energy Investigation
Choose one of the springs used in Part 1 and select a mass that provided a noticeable stretch to the spring but not so drastic that it will not be able to be stretched further
Record the mass you will use and describe which spring you chose to use
____________________________________
____________________________________
____________________________________
____________________________________
We will use the provided rings to setup the apparatus show in the diagram, follow the steps below:
Attach the mass to the spring.
Hold the mass so that the spring does not stretch but will be at its relaxed length .
Move the top ring so that it will mark the location of the bottom of the mass while you a holding it at its relaxed position re
READ THE WHOLE STEP BEFORE DOING IT
DROP the mass from the relaxed length so that it falls down and stretches the spring. Watch it as it falls and make a note of where it momentarily stops at the lowest position before it bounces back up. Slide the lower ring up and down on the stand to mark this lowest position.
REPEAT this drop a series of times until you have accurately marked the lowest position of the mass. THE LOWER RING SHOULD BE AT A
LOCATION BELOW THE MASS WHEN IT HAS
FINISHED BOUNCING.
Measure the length between the rings to get a value for the maximum stretch (change in length) of the spring and record that value
________________________________

Part 1
1.) For one of your springs and masses, draw a FBD of the spring at its relaxed length and next to it draw a second FBD when the mass was attached to the spring. Label the lengths and the change in length as well as the forces acting when the mass is attached to the spring

2.) Collect your data in the tables below and determine the weight ( = spring force)
Rubber Band
Mass
(kg)
F
SP
= F
(N)
G
Initial L (x
(m) o
) Final L (x)
(m)
Δ x
(m)
Spring 1 – Describe Spring Here __________________________
Mass
(kg)
F
SP
= F
(N)
G
Initial L (x
(m) o
) Final L (x)
(m)
Δ x
(m)
Spring 2 – Describe Spring Here __________________________
Mass
(kg)
F
SP
= F
(N)
G
Initial L (x
(m) o
) Final L (x)
(m)
Δ x
(m)
Spring 3 – Describe Spring Here __________________________
Mass
(kg)
F
SP
= F
(N)
G
Initial L (x
(m) o
) Final L (x)
(m)
Δ x
(m)

3.) Make a separate XY scatter Graph of Force vs. Stretch for each spring and/or rubber band and be sure title each one with the type of object used as well as the variables force and stretch (Note: you should remember how to tell which one is the y value based on the “vs” terminology, look it up if you forgot). MAKE A SEPARATE
GRAPH FOR EACH SPRING on its own page . Be sure to put a best fit line or curve on the graph. NOTE: if the best fit is a curve, which it probably will be for some of them, put this best fit curve in, and then after you print the graph, draw a linear straight line to represent a representation of the average slope of the graph if the relationship were linear. This is very important and is what you will use to find the spring constant for a graph that is naturally curved and not linear. Some of your data might be naturally linear and not have this problem.
Make the graph sized at least a half of a piece of paper. You can copy and paste the graph from excel into word in order to do this .
4.) Below each graph, pick appropriate points and find the slope of the graph to determine the spring constant.
Be sure to indicate which points you are using and circle them on your graph as well. (Note: DO NOT PICK
POINTS from the graph and plug into F=kx, and don’t average individual k values either. Rather you should be finding the slope to get the spring constant) .
5.) Below each graph, state whether or not the spring constant is actually constant for the spring or shows variation based on the stretch and explain how you make this conclusion.
6.) Use each graph to determine the amount of work that would be done by the spring as mass was added. Use the lowest amount of attached mass as the starting point and determine the work done as the spring was stretched from this position to the final largest stretch position recorded. Clearly show your answers below each graph and explain how you found the work in each graph.
Part 2 -
The diagram below represents the motion of the spring in Part 2 of the lab. It started at rest at position A and then was dropped until it stretched and reached position B where it momentarily stopped again.
(starting position)
\ \
/ /
\ A \
/
For this part of the analysis, we are going to assume that when the spring reached position B, the max stretch, it was at a height of zero h = 0
h
A
\
B (Max stretch)
(a) What kind of PE would the system posses at point A, calculate it
(b) What kind of PE would the system posses of point B, calculate it
(c) How should the results to parts (a) and (b) compare to each other. Explain in detail why they should be this way and comment on how your results compare to what you would expect.

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• The “dynamics cart” should have both the spring loader and the “Angle Indicator” attached to it which is used to break the laser of the photogate. If they are not attached ask your teacher.
____ 1) Measure the length of the narrow middle part of the “Angle Indicator” (as shown in the diagram below)
Record the measured length here:
__________ L
____ 2) The “dynamics cart” should be placed on the track, with the spring launcher inserted into the black end stop and the spring uncompressed. With the cart in this location, put one of the photogates about 10 cm away from the front of the cart. Then put the second photogate about 50 cm away from the first photogate
(see figure 1 below)
____ 3) Adjust the height of each photogate so that the thin middle part of the Angle Indicator will be the part that breaks the laser as the Angle Indicator moves through each photogate. You can see the location of the laser sensor on the photogate by inspection. You must carefully set its height so that the Angle Indicator will not hit the photogate and so that only the thin middle part passes by the laser sensor
____4) Using one of the scales in the classroom, record the mass of the Dynamics Cart. Also find the mass of the Collision Cart and add extra 20 and 50 gram masses so that it has nearly the same mass as the dynamics cart. Record the total masses below.
= ___________ kg Dynamics Cart mass m
1
Collision Cart mass m
2
= _____________ kg
____ 5) Place the Collision Cart about 30 cm away from the first photogate. The location should be such that when the dynamics cart is launched it will pass through the first photogate by itself; then collide with the Collision
Cart, and the two of them will then pass through the second photogate together.
FIGURE 1 (not to scale)
Spring launcher Angle Indicator Photogate 1 Photogate 2
End Stop extra masses
Dynamics Cart Collision Cart
10 cm 30 cm
50 cm
___6) Turn on, Reset the photogates, and make sure they are in “gate” mode

___7) Pull back on the spring launcer to compress the spring fully and release to fire the Dynamics Cart forward.
It should pass through the first photogate, collide and STICK TO the Collision cart and then both of them should pass through the second photogate. MAKE SURE THAT THE CARTS DO NOT BOUNCE OFF THE SECOND
END STOP AND COME BACK THROUGH THE PHOTOGATES.
___8) Record your Data as follows: be sure to read carefully. a) The time listed on the photogate at the end of the experiment is the time it took the Angle Indicator (length L) to pass through the first photogate. We will call this t
1
. Record this time in the chart on the next page. b) The photogates also record the total time that both photogates were active for (t
1
+t
2
) which can be seen by clicking down to the “read” setting on the silver lever switch marked “memory” on the photogate (be aware that clicking this lever will permanently erase the first time and only show the total ). This total time (t relevant to us, rather we want just time t
2
So take the total time and subtract the first reading (t
1
) to get the time t
2
1
+t
2
) is not
(time for the Angle Indicator to pass through the second photogate).
and record it in the attached chart. c) The velocity of each part can be found by using v= d / t with the d being the length L of the angle indicator
for each photogate and the time being the individual times t
1
or t
2
___ 9) Each lab table has a series of long and short bar masses on them. Use the scales in the classroom to determine the masses of each of these bars
Bar Masses short _______ kg long _______ kg
___10) Remove the small extra masses added to the collision cart previously. Add the bar masses to the carts in different variations to create more collision trials with varying amounts of mass in each cart. Record your data and complete the attached table with a variety of trials. (Be sure to subtract off the small mass values when recording total mass of the collision cart)
___ 11) Determine the percent error using the initial momentum as the actual value.

Recorded Data
Trial
Number
Total Mass
(m
1
) of
Dynamics
Cart (kg)
Total Mass
(m
2
) of
Collision
Cart (kg)
Length (L) of Angle
Indicator
(m)
Photogate
Time (t
1 prior to
) collision
(sec)
Sample Calculations
Photogate
Time (t
2
) after collision
(sec)
Calculations
Velocity (v
1
) of Dynamics
Cart prior to collision
(m/s)
Velocity (v
2
) of Combined
Carts after collision
(m/s)
Total
Momentum
(p
1
) Before
Collision
(kg m/s)
Total
Momentum
(p
2
) After
Collision
(kg m/s)
Percent
Error of
Momenta

Questions
1.) Give reason for error in this experiment
2.) Did momentum conservation seem to hold true? Explain, and comment on which types of trials seem to conserve momentum the best.
3.) (a) For trial number 1, use the recorded cart masses and initial velocity v theoretical value for final velocity of the combined masses after the collision. (This calculation should be done without the measured time t
2
1
of the dynamics cart to determine a
2
from the lab data.
, rather should be based on physics principles of solving collision problems) (b)
Determine the percent error of this calculated velocity vs. the measured experimental v

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Introduction: Static Electricity Investigation Lab
Part A - Polarity test (+ or -)
Materials Provided
- Pith ball (small Styrofoam ball with a conductive coating allowing it to be charged)
- Rubber Rod
- Glass Rod
- Cotton Felt
- Silk
- Rabbit Fur
- Clear Acetate strip
- White Vinyl strip
Definitions:
(1) A rubber rod rubbed with fur or wool acquires a negative charge
(2) Like charges repel and opposites attract
Procedure:
1.) Using only the definitions and materials provided above. Devise a test to determine the type of charge on an object and explain how your test will work. (The use of the pith ball is necessary every time and is the
main object to help in your test)
2.) Use your test to determine the sign (+/-) of the materials below
(a) Vinyl strip (white) rubbed with fur
(b) The fur from (a)
(c) Acetate strip (clear) rubbed with cotton felt
(d) Glass rod rubbed with silk
(e) A pen stroked on your hair.
Part B - Attraction or Repulsion

(a) Use your results from PART A (Polarity test) of this lab to positively charge an object. Charge the pith ball positively by contact. Bring a negative charge near it and then a positive charge but do not allow the charge to touch the ball. Describe and explain the results?
(b) Discharge the pith ball completely by holding it in your hand and letting your body act as a ground. In terms of movement of electrons, explain what happened when you touched the ball.
- Bring a negative charge near the neutral pith ball but don’t let it touch.
- Bring a positive charge near the neutral pith ball but don’t let it touch.
What results do you observe? Why does this happen?
(c) Based on the results above, which is better proof of a charged object, attraction or repulsion? Explain by using your results from (a) and (b)

Part C – Using an Electroscope
Note: When charging the electroscope by contact, it helps to rub the charged rod back and forth on the top plate
(a) Use the rubber rod and rabbit fur to negatively charge an electroscope by contact. Explain the electron flow between the three objects (fur, rod, electroscope) that allows the electroscope to become charged
(b) Use your results from PART A (Polarity test) of this lab to positively charge an object. Bring the positively charged object, near but not touching the negatively charged electroscope. Record your observations and explain what you observe.
Part D – Charging by Induction
(a ) Discharge the electroscope completely by using your body as a ground. Bring a charged negative rod near but not touching the electroscope. By not touching the electroscope, no charges will be transferred from the ro d.
Describe and explain the results in terms of electron flow?
(b) Move the rod away. What does the position of the pin indicate about the charge on the electroscope and why does this happen?

(c) READ THE WHOLE STEP BEFORE PROCEEDING. Bring the charged rod near again. While it is near one side of the electroscope touch the other side with your finger. Keep your finger on it and the rod nearby. Remove your finger from the scope first, and then remove the rod. You have now induced a charge on the scope and should see deflection of the needle.
(d) Perform a test to determine the polarity (charge) of the electroscope. Describe what happened when you performed this test and why this showed you what sign the charge on the electroscope was?
(e) In step C the electroscope was charged by induction. Create diagrams of each step in this process and explain what is happening in each step in terms of electron flow.

Name:   _______________________________
Introductory   Notes:
Connecting   Voltmeter
When   hooking   up   voltmeters   to   measure   voltage,   be   aware   of   the   following:
1)   Put   the   meter   in   parallel   (around)   the   device   being   measured   as   shown   below.
2)   Connect   the   plugs   on   the   meter   itself   so   that   one   is   plugged   into   the   “COM”   port   and   the   other   to   the   “V”   port
3)   Set   the   meter   to   DC   Voltage   setting   on   the   turn   dial.
Connecting   Ammeter
When   hooking   up   ammeters   to   measure   current,   be   aware   of   the   following:
1)   Put   the   meter   in   series   (next   to)   the   device   being   measured   as   shown   below.
2)   Connect   the   plugs   on   the   meter   itself   so   that   one   is   plugged   into   the   “COM”   port   and   the   other   to   the   “10   A”   port
3)   Set   the   meter   to   10A   setting   on   the   turn   dial.
V1

Lab   Procedure   /   Analysis
1)   Draw   a   schematic   of   a   single   bulb   in   series   with   a   battery   and   an   ammeter   and   voltmeter   connected   to   measure   current   and   voltage   of   the   bulb.
2)   Setup   the   multimeter   as   described   on   the   prior   page   to   function   as   a   voltmeter.
(be   sure   to   connect   the   plugs   properly   and   set   the   turn   dial)
3)   Single   Bulb:   Connect   a   single   bulb   to   the   battery;   then   connect   the   multimeter   (voltmeter)   to   measure   the   potential   of   the   bulb   as   shown   on   the   prior   page.
Record   results   on   the   table   on   the   next   page.
4)   Disconnect   the   multimeter   and   set   it   up   as   described   on   the   prior   page   to   function   as   an   ammeter   (be   sure   to   move   the   plugs   and   set   the   turn   dial).
Connect   to   the   single   bulb   and   record   the   measured   current   in   the   data   table.
5)   Bulbs   in   series:   Add   a   second   bulb   to   the   circuit   in   series.
Setup   the   multimeter   as   a   voltmeter   (be   sure   to   move   the   plugs   and   set   the   turn   dial),   and   measure   the   voltage   directly   from   the   battery   and   directly   from   each   bulb.
Then   setup   the   multimeter   as   an   ammeter   (be   sure   to   move   the   plugs   and   set   the   turn   dial)   and   measure   the   current   directly   after   each   device   (battery,   bulb1,   bulb2).
Record   results.
Disconnect   your   wires   and   move   to   step   6.
6)   Bulbs   in   parallel   are   slightly   harder   to   connect.
To   make   measurements   the   easiest,   it’s   best   to   create   a   junction   with   your   wires   so   the   ammeter   is   very   easily   moved   through   the   circuit.
You   will   have   to   clip   multiple   wires   onto   each   other   to   create   these   junctions,   see   the   diagram   (the   wires   have   been   numbered   for   you)   and   connect   the   bulbs   as   indicated.
7)   Setup   your   multimeter   to   function   as   an   voltmeter   (be   sure   to   move   the   plugs   and   set   the   turn   dial)
8)   After   assembling   your   circuit,   clip   the   multimeter   (set   as   a   voltmeter)   directly   in   parallel   with   the   battery   to   record   the   total   voltage   of   the   battery.
Then   move   the   voltmeter   to   each   bulb   to   measure   the   voltage   across   each   bulb   and   record   results.
8)   Set   the   multimeter   to   ammeter   operation   and   connect   it   first   directly   in   series   with   the   battery,   then   directly   in   series   with   each   bulb   and   measure   all   three   currents   and   record   them   in   the   table   that   follows.
V2

Simple   Circuit   Lab   Results
DATA
Device single   bulb series   (2   bulbs) battery bulb   1 bulb   2 sum   bulb   1+2
Voltage(V) Current(A)
Questions/Calculations
1)   Referring   to   the   results   above,   do   the   rules   for   current   and voltage   seemed   to   be   verified   for   series   circuits?
explain
(for   this   question   only,   ignore   slight   variations   in   the   data)
Name:   _______________________________________________ parallel battery bulb   1 bulb   2
(2   bulbs) sum   bulb   1+2
Voltage(V) Current(A)
2)   Referring   to   the   results   above,   do   the   rules   for   current   and voltage   seemed   to   be   verified   for   parallel   circuits?
explain
(for   this   question   only,   ignore   slight   variations   in   the   data)
3)   Justify   any   slight   variations   that   you   may   have   seen   in   voltages   during   the   lab   and   in   relation   to   questions   1&2   as   to   how   the
data   compares   to   expected   results   for    current   and   voltage   in   series   and   parallel   circuits.
V3

Recopy   your   data   from   page   one   into   this   chart.
DATA
Device single   bulb
Voltage(V) Current(A)
Voltage(V) Current(A) series   (2   bulbs) battery bulb   1 bulb   2 sum   bulb1+2 parallel   (2   bulbs) battery bulb   1 bulb   2 sum   bulb1+2
4)   From   the   standpoint   of   the   overall   circuit   as   a   whole   (equivalent   resistance),   compare   the   total   current   flowing   from   the   battery
with   the   single   bulb,   to   the   total   current   flowing   from   the   battery   when   both   bulbs   were   connected   in   series,   explain   the   results.
5)   Answer   question   #4   for   the   parallel   connection
6)   In   the   space   below,   calculate   the   resistance   of   each   bulb   for   each   setup   (show   your   work   only   for   the   single   bulb   calculation)
Single   bulb Bulb   Resistance
7)   Referring   to   the   results   from   question   6,   does   the   resistance   of
the   bulb   remain   constant   regardless   of   how   it   was   connected?
Justify   and   explain   your   results.
Series   bulbs
Parallel   bulbs
Bulb
Bulb
1
1
Resistance
Resistance
Bulb   2   Resistance
Bulb   2   Resistance
V4

pendulum
cycle
period
amplitude
•
•
•
cycle
period
amplitude
•
•
•

(seconds)
(seconds)
Graph your data: Make sure that the scale on your x and y axis is appropriate (do not make your scale over a very short range, rather use a normal number scale). Be sure to title it and label everything.
Also, remake this graph using Excel and attach it (you will have to adjust the axis max and min scale setting).

(degrees)
(seconds)
(seconds)
Also, remake this graph using Excel and attach it (you will have to adjust the axis max and min scale setting).

(cm)
(seconds)
(seconds)
Also, remake this graph using Excel and attach it (you will have to adjust the axis max and min scale setting).

1.) Which factor has the largest effect on pendulum period?
2.) Explain the actual physics reasons why each factor had or did not have an effect on the period. Do not simply state that the factor is not in the formula, rather give actual physical reasons for each effect based on forces, masses and the motions themselves.
------------ Continued --------------

3.) The equation for the period of a pendulum on a string is
T
=
2
π l g
Chose 1 set of results and calculate an experimental value of g based on the length of the string in that setup.
Compare (% error) the calculated value of “g” to the actual known value. Be sure to explicitly state which measured values you are using and show all work and substitution when solving for the unknown.

The purpose of this lab is to demonstrate resonance of sound waves and determine the speed of sound traveling in air.
Resonance tube (graduated cylinder and inner glass tube), water, tuning forks, meter stick,
1) Fill the 1 liter graduated cylinder to within two inches from the top with water. Place the inner tube inside the graduated cylinder.
2) Choose a tuning fork and record its frequency. f =_________________ Hz
3) Strike the tuning fork with hard rubber and hold the tuning fork horizontally, with its tines one above the other about 1 cm above the open end of the inner tube. Move both the inner tube and the fork up and down together to find the air column length that gives the loudest sound. Measure the distance from the top of the resonance tube to the water level.
Length of the resonance tube = _______________ m
4) Record the diameter of the resonance tube. Diameter of the resonance tube = ______________ m
5) The air which vibrates and makes sound actually extends slightly beyond the length of the tube itself and we therefore need to make a correction to find the actual length of air vibrating. This correction is made by adding
0.4 times the diameter of the tube to the measured length of the air column.
Corrected Length = _______________m
6) The vibrating air creates a fundamental standing wave in an open/closed pipe. As such, the length of the tube measured only holds ¼ of the wavelength of the wave (see diagram).
Using this fact, determine the wavelength of the sound
(be sure to use the corrected length when doing this).
READ THIS STEP CAREFULLY, READ IT AGAIN TO
L
BE SURE YOU UNDERSTAND WHAT IT IS SAYING.
Wavelength = _______________m
7) Determine the velocity of sound and record. work.
Speed of sound in air = ____________m/s

8) Repeat each of the above steps for a second tuning fork: f = ______________ Hz
Length of the resonance tube = ______________ m
Corrected Length = ______________ m
Wavelength = ______________ m
Speed of sound in air = ______________ m/s.
The accepted value for the speed of sound in air is 332m/s at 0C.
The speed of sound in air increases by 0.6m/s for each degree C above zero.
Using the temperature of the room today, compute the accepted value for the speed of sound at room temperature.
Calculate the percentage difference between this and the average of your two measured values.

Handheld Laser
Ruler
Protractor
Semi-Circular dish
1.) Take out the laser and put the batteries in. Keep the laser dry.
2.) Take a sheet of paper and place the semi-circle dish upside down in the center of the paper (open side down). Trace the shape of the dish on the paper and remove the dish from the paper.
3.) Repeat step 2 again so you will have two sheets with tracing on them, let each lab partner trace the shape twice as well.
4.) Fill the dish about halfway with water.
5.) Add two drops of milk to the dish and stir them into the water. The small amount of milk will make the laser visible in the water, like fog makes lasers visible in air. Shine the laser through the side of the container to verify that you can see it in the water, if not add a little more milk, but not too much.
6.) Place the semi-circle dish back on the traced paper shape and shine the laser directly perpendicular to the flat face as shown in the diagram below. Keep the laser and the paper dry. dish
paper
WHEN USING THE LASER, IT WORKS
BETTER IF YOU RAISE IT VERY
SLIGHTLY OFF THE PAPER SURFACE
SO THE LIGHT RAY DOES NOT HIT
THE BOTTOM OF THE DISH ON THE
PAPER.
laser
QUESTION:
Do you see refraction when the laser enters the dish in the configuration, explain?

7.) Using the same setup as before, change the laser orientation so that it is angled to the flat side of the dish and hits the midpoint of the dish (see diagram). Again hold the laser slightly above the paper surface. dish
paper
laser
QUESTION :
Do you notice refraction when the laser enters the water, explain?
8.) We are going to make 3 dots to show the path of the laser beam. Using a pencil:
1 - Place a dot (1) at the tip of the laser where the light beam originates,
2 – Place a dot (2) where the beam first hits the flat side of the dish.
(MAKE SURE THE DOT IS PLACED EXACTLY ON THE TRACED LINE, AND NOT ABOVE OR BELOW)
3 – Place a dot (3) where the beam exits the water dish
dot 3
dot 2
dot 1
9.) Remove the laser and dish and USE A RULER to connect the dots with arrowheads to show the path of the light.
10.) Repeat so each lab partner has their own paper.

dot 2

1.) Using the same setup as before, place the dish on the second traced sheet.
2.) Turn the paper around 180 degrees so that the circular side is facing you. dish
laser
paper
In this part of the lab, the laser should always be exactly perpendicular to the curved surface.
3.) Move the laser right next to the curved surface of the dish, holding it slightly off the paper, and hold it so that the laser light is perpendicular to the surface of the dish. Notice the light ray moving through the water and also notice a second ray exiting the water into air at the flat side. If you cannot see the exiting ray, put something a few centimeters behind and to the side of the flat side of the dish so you can see a dot showing where the exiting laser goes.
4.) Slide the laser from its current position along the curved face always keeping it perpendicular to and touching the dish, and pay attention to the ray exiting at the flat side of the dish, see diagram. The laser should be hitting the flat side at the midpoint . Continue to move the laser until the exiting ray no longer exits the water, but all reflects back inside, this is the critical point for total internal reflection. Slide the laser beam back and forth to verify you have found the exact position of total internal reflection
5.) We will again make dots to mark the position of the light ray. Make one dot at the tip of the laser where the ray enters the water, make a second dot where the laser hits the flat part of the dish, and make a third dot where the reflected ray comes back to the curved surface
dot 2
dot 3 dot 1
6.) Remove the laser and dish, and USE A RULER, to draw the rays. Repeat for other lab partners.

Part 1 - Refraction
1.) Using your sketch from part 1, USE A RULER and draw a normal line at the flat surface and label the incident and refraction angle on the diagram, make the normal line long so you will be able to measure the angles properly. Accurately, measure incident and refraction angles with a protractor and use the table below to record them. Also label them on the diagram itself.
θ i
θ r
2.) Using the angles above and the situation shown in the diagram, calculate a value for the index of refraction of water. Show all formulas and work.
3.) Compare your value of n water and work.
with the best known value n water
= 1.33. What is the % difference? Show formula

Part 2 – Total Internal Reflection
1.) Using your sketch from part 2, USE A RULER and draw a normal line at the flat surface and label the incident and REFLECTION angle on the diagram, make the normal line long so you will be able to measure the angles properly. Accurately, measure incident and reflection angles with a protractor and record them in the chart below, also record them on the diagram itself.
θ i
θ c
θ ’
NOTE: θ ’ IS NOT THE REFRACTION ANGLE.
2.) Based on the values from the chart, is the “Law of Reflection” verified, explain?
3.) The incident angle measured in step is the critical angle ( θ i
= θ c
) determined experimentally since it was just at the point where total internal reflection occurred. We are looking at the point where the laser was in the water and was trying to get into the air, so this is the medium boundary you should be looking at (water to air).
Calculate a theoretical value for the critical angle based on the medium conditions water-air.
4.) Compare your measured experimental value of the critical angle to the theoretical actual one found in part 3, compute a percent error and state justifications for possible error.

Buoyancy Lab
Purpose:
Name: __________________
Investigation of density, specific gravity and buoyancy.
Procedure:
Part I
1.) For each provided metal cube, use the digital scales to determine the masses.
2.) Measure the dimensions and determine the volume of each cube.
3.) Calculate the density of each cube in kg/m  3  and also determine the specific gravity of each.  Make a table  below to hold your values.  Also show a sample calculation. (you might not use every column)
AD1

Part II
1.) Using the provided water bath and spring scale, determine the actual weight of each cube, the apparent  weight of each cube in water, and the buoyant force acting on each object.
2.) Using the known value for the density of water and only the values found above, determine the volume,  density and specific gravity of each object.
Make a table to hold your values.  Also show sample calculations.  (you might not use every column)
Determine a percent error between the two specific gravity results from part 1 and 2 for each cube.
AD2

Part   I   –   Static   Friction   2   ways.
Note:   Boxed   sections   should   be   completed   today.
A.)   Force   Scale
1.) Using   the   digital   balance;   determine   the   mass   of   the   cart   and   block   separately,   then   put   the   wood   block   with   the   soft   velco   facing   up   into   the   dynamics   cart.
Record   data   here   :    m cart
=   ____________,   m block
=   ____________
2.) Turn   the   cart   and   block   upside   down   on   the   track   so   that   the   soft   Velcro   touches   the   track.
3.) Put   a   1   kg   hex   mass   on   top   of   the   upside   down   cart   ...
list   new   total   mass   here   M total   =   _______________
4.) Using   a   force   scale,   determine   the   static   friction   maximum,   repeat   to   verify,   record   data   here:   fs(max)   =   ___________
Determine   the   coefficient   of   friction   from   the   values   in   part   A,   show   work:
B.)   Angle   of   Repose   (The   angle   of   repose   is   the   angle   at   which   an   object   first   begins   to   slip)
1.)   Use   the   same   setup   as   above,   except,   rather   than   using   the   force   scale,   slowly   incline   the   dynamics   track   until
the   cart   begins   to   slide,   repeat   to   verify   your   results   and   record   the   angle:
Determine   the   coefficient   of   friction   from   the   values   in   part   B   ,   show   work:
θ   =   __________
Compare   your   answers   to   A   and   B   and   comment   on   the   results
AE1

Part   II   –   Tension   in   a   Rope.
1.) Using   two   force   scales   and   the   hex   mass,   setup   the   diagram   shown   below   with   two   different   angles;
Record   the   readings   on   both   force   scales,   the   angles,   and   the   value   of   the   hanging   mass   directly   on   the   diagram:
θ
1
θ
2 m the   value   of   the   attached   mass   and
Determine   a   theoretical   value   of   the   tension   in   the   ropes   based   on   the   angles
Percent   Error:
Find   a   percent   error   between   the   theoretical   and   experimental   tensions
AE2

Part   III   –   Newtons   Second   LAW.
Introduction   to   Photogates.
‐ A   photogate   is   a   laser   timing   device   that   looks   like   this   Æ
‐ When   an   object   passes   through   the   laser,   the   photogate   will   record   the   amount   of   time   that   it   takes   the   length   of   that   object   to   pass   through.
Using   v=d/t   we   can   then   determine   the   velocity   of   the   object   as   it   passes   through   the   photogate.
This   is   called   “Gate   Mode”   on   the   photogate   timer.
The   “d”   in   this   scenario   is   the
length   of   object   breaking   the   laser   laser
IMPORTANT :   In   gate   mode,   both   times   are   stored   in   memory   in   a   strange   fashion...
When   reading   the   values   from   the   timer   display,   the   first   time   listed   will   show   the   time   it   took   to   pass   through   the   first   gate;   then   if   you   then   click   the   timer   to   the   READ   position,   it   will   show   the   sum   of   both   times   from   each
gate   so   you   have   to   subtract   the   first   time   value   given   in   order   to   find   the   time   for   the   second   gate.
‐ Alternately,   two   photogates   can   be   used   when   the   photogate   timer   is   set   to   “Pulse   Mode”.
In   this   mode   the   photogates   will   record   the   time   it   takes   to   pass   from   one   photogate   to   another   giving   you   the   total
time   it   takes   to   cover   a   fixed   distance.
The   “d”   in   this   scenario   is   the   spacing   of   the   photogates.
Procedure:
Setup   the   apparatus   shown   below   using   two   photogates.
‐ Put   the   photogate   connected   to   the   main   control   box   as   the   first   one   next   to   the   cart.
Use   'GATE'   mode
‐ Put   the   ‘angle   finder’   in   the   cart   as   shown   and   adjust   the   height   of   the   photogates   so   that   only   the   center   of   the   angle   indicator   (marked   “d”   in   figure)   passes   through   the   photogate   laser   (note:   the   laser   location   can   be   seen   by   looking   at   the   light   on   the   outside   of   the   photogate   near   the   opening).
‐ Measure   and   record   distances   “L”   and   “d”   on   the   diagram   below.
L               Angle   Indicator
d
Cart (M
2
)
Hanging   Mass
Photogate   2 Photogate   1
M
1
Experiment
‐  Use   100   g   of   mass   for   mass   M
1
(the   hanging   mass)   for   the   entire   experiment
‐  Put   a   variety   of   100   and   200   g   masses   into   the   cart   ( make   sure   they   are   on   their   side   so   they   don’t   disrupt   the
photogate   laser)
‐  Release   the   hanging   mass   and   record   the   times   from   both   photogates   1   and   photogates   2   in   the   data   table
(remember,   you   have   to   subtract   the   second   reading   from   the   first   to   get   the   time   for   the   second   photogate,   see   instructions   from   introduction)
AE3

‐  Continually   remove   masses   from   the   cart   and   repeat   the   experiment   to   obtain   various   trials.
Data   Table:    All   Data   should   be   recorded   below.
Note:   Experimental   Acceleration   is   not   technically   'data'   as   you   will   have   to   calculate   it
Hanging
Mass
M
1
(kg)
Angle finder distance
"d"
(m)
Distance between gates "L"
(m)
Cart +
Masses
M
2
(kg)
Gate 1 time - t
1
(s)
Gate 2 time - t
2
(s)
Experimental
Acceleration
(m/s 2 )
Sample   Calculation :   Show   a   sample   of   how   experimental   acceleration   is   calculated   using   the   distances   and   times
recorded   from   the   table.
Graph  ‐  Create   a   graph   of   total   mass   (M
1
+   M
2
)   vs.
experimental   acceleration   on   a   full   page   at   attach   it   to   the   lab.
Since   the   hanging   mass   was   kept   constant,   this   graph   will   be   a   graph   showing   the   relationship   between   mass   and   acceleration   when   the   force   causing   the   acceleration   remains   constant.
On   the   graph,   specifically   comment   about   the   relationship   shown   and   whether   or   not   it   makes   sense   based   on   the   second   law   equation   and   prediction   of   expected   results.
AE4

Theoretical   Acceleration  ‐  Using   the   idealized   diagram   of   the   setup   below   and   the   recorded   masses   from   row   1
of   the   lab   (and   assuming   no   friction),   determine   a   theoretical   value   for   the   acceleration   of   the   system   showing   all   work.
Cart(m
2
)
hanging   mass   (m
1
)
Percent   Error:
Find   a   percent   error   between   the   theoretical   acceleration   and   experimental   acceleration,   comment   on   sources   of   error.
AE5