MIDDLE SCHOOL SCIENCE
Lab Manual
Grade 7
Mr. Bretl
2013 -­‐ 2014 Middle School Science Lab Safety Rules and Procedures
Rules and Procedures:
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Read the entire lab before you begin and follow all lab instructions exactly as explained by your teacher.
There is a zero tolerance policy for any form of horseplay during a lab. If you are unclear about a
certain portion of the lab, ask your teacher.
Any accident, regardless of the severity, must be reported to the teacher immediately. Always transport
scissors or other sharp objects with the sharp end down; always cut away from yourself during
dissection or other lab procedures.
Eating and drinking is strictly forbidden during labs; only eat, smell, or taste an item if told to do so by
your teacher.
Know the location and use of all safety equipment in the lab, which includes: goggles, aprons, eye wash,
fire blanket, fire extinguisher, lab shower, safety charts, MSDS binder and sharps/broken glass container.
Report any damaged or broken equipment to your instructor immediately.
Check cords and plugs for damage and keep the area dry when working with electrical equipment.
Clothing and Safety Equipment:
Baggy clothes and long hair must be neatly secured while performing any experiment.
Safety Goggles must be worn when:
o Working with any form of heat
o Working with chemicals
o Working with sharp objects
o Determined by the teacher
Chemicals:
• Only mix chemicals in the order described within the lab. Always add acid last.
• When smelling any chemical or substance, do so by wafting.
• All chemicals and/or any lab supplies must be accounted for at the completion of the lab. No chemical,
item, or specimen should ever leave the lab room.
• Chemicals splashed on the skin or eyes should be flushed with water for a minimum of 20 minutes.
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Lab Cleanliness:
• Keep your lab area neat and clean. Always dispose of chemicals properly and never return unused
portions to the original container.
• Solid trash should be placed in the trashcan; liquid wastes should be placed in the sink with lots of water
or other designated disposal area as determined by your instructor. (Broken glass goes in the sharps
container)
• All equipment must be thoroughly cleaned at the conclusion of the lab and returned to the assigned area.
Wash your hands at the end of each lab!
Parent Signature_________________________________________________ Date_______________
Student Signature_______________________________________________ Date_______________
LAB 1 – The Scientific Method and Metric System
Part 1: The Scientific Method
The field of science is based on observation and measurement. If a scientist cannot observe
and measure something that can be described and repeated by others, then it is not considered
to be objective and scientific.
In general, the scientific method is a process composed of several steps:
1. observation – a certain pattern or phenomenon of interest is observed which leads
to a question such as “What could explain this observation?”
2. hypothesis – an educated guess is formulated to explain what might be happening
3. experiment – an experiment or study is carefully designed to test the hypothesis,
and the resulting data are presented in an appropriate form
4. conclusion – the data is concluded to “support” or “not support” the hypothesis
To illustrate the scientific method, let’s consider the following observation:
A scientist observes that Compound X appears to increase plant growth, which leads
to the question: “Does Compound X really increase plant growth?”
Hypotheses
The next step in applying the scientific method to a question such as the one above would be
to formulate a hypothesis. For a hypothesis to be a good hypothesis it should be a statement
of prediction that:
a) uses objective, clearly defined terms
b) can be tested experimentally
A reasonable hypothesis regarding the observation on the previous page would be:
Increasing amounts of compound X correlate with increased plant height.
In this case there is nothing vague or subjective in the terminology of the hypothesis, and it
can easily be tested experimentally, so it’s a good hypothesis. Keep in mind that a good
hypothesis is not necessarily correct. If a hypothesis is clear and testable and experimentation
disproves it, valuable information has been gained nonetheless. For example, if testing the
hypothesis “supplement Y is safe for human consumption”, it would be very valuable to
know if experimental data does not support this hypothesis.
Exercise 1A – Good vs bad hypotheses
Indicate whether or not you think each hypothesis listed on your worksheet is “good” or “bad”.
Experimentation
Experiments are designed to test hypotheses. A simple test of the hypothesis on the previous
page would be to plant the seeds of identical pea plants in pots containing the same type of
soil, being sure that each pot is exposed to the same temperature, pH, amount of sunlight,
water, etc, and measure their height after a 5 week period. The only difference between these
plants will be amounts of Compound X given to the plants each day, which are as follows:
Pea Plant
1
2
3
4
5
6
Compound X per Day (grams)
0
1
3
5
7
9
In testing the effects of Compound X on pea plant growth, it is common sense that you should
devise an experiment in which multiple pea plants are grown under identical conditions
except for 1 difference or variable, the amount of Compound X given to each plant. In this
way any differences in plant height should be due to the only condition that varies among the
plants, the amount of Compound X.
When you design an experiment or a study such as this, it is important to consider all of its
components. Even though we design the experiment to contain only 1 variable component,
we need to consider all other components including the outcome of the experiment and any
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control experiments that are done. Thus, when designing an experiment you need to account
for the following:
independent variable
the treatment or condition that VARIES among the groups
dependent variable
the MEASUREMENTS or outcomes recorded at the end of the experiment
standardized variables
all other factors or conditions in the experiment that must be kept the same
(e.g., type of soil, amount of water, amount of sunlight) so their influence on
the dependent variable remains constant (i.e., we want to measure the effect of
the independent variable only)
experimental groups/treatments
the subjects (e.g., plants) that receive the different treatments
control group/treatment
the subjects that receive NO treatment, i.e., the independent variable is
eliminated (set to “zero”) or set to a background or default level
(NOTE: control treatments for independent variables such as temperature and
pH that cannot be eliminated are generally at a “background” level such as
room temperature or pH = 7)
Repetition is also important for an experimental result to be convincing. There needs to be a
sufficient number of subjects and repetitions of the experiment. For example, to make this
experiment more convincing multiple plants would be tested at each level of the independent
variable and it would be repeated multiple times.
Data Collection & Presentation
Upon completion of an experiment, the results need to be collected or measured, and
presented in an appropriate format. For our sample experiment, after 5 weeks the height of
the pea plants is measured and the following data are collected:
Pea Plant
1
2
3
4
5
6
Compound X per Day (grams)
0
1
3
5
7
9
3
Height of Plant (centimeters)
4.0
9.9
13.2
15.1
16.8
17.0
Now that you have the raw data for the experiment, it is important to present it in a form that
is easy to interpret. Frequently this will be in the form of a table, chart or graph. The data
above are presented in a table, however the overall results will be easier to interpret if
presented in a graph.
There are many ways to present data graphically, but the two most common types of graphs
are line graphs and bar graphs. When graphing data in this way, it is customary to place the
independent variable on the X-axis (horizontal) and the dependent variable on the Y-axis
(vertical). The independent variable in this experiment is the “amount of Compound X
added” and the dependent variable is the height of pea plants after 5 weeks. Below are the
Compound X data presented in a line graph on the left and a bar graph on the right:
plant height
18
18
16
16
14
14
12
12
plant height
10
8
6
8
6
4
4
2
2
0
0
0
10
1
2
3
4
5
6
7
8
9
10
1
grams of Compound X
added
3
5
7
9
grams of Compound X
added
Which type of graph is best for this data? It depends on the nature of the independent
variable on the X-axis. If the independent variable is continuous (i.e., there are values for the
independent variable that fall between those actually tested), then a line graph would be
appropriate. This would be the case if the independent variable covered a range of values for
time, temperature, distance, weight, or volume for example. In our example, the “grams of
Compound X” is clearly a continuous variable for which there are values in between those
tested, therefore a line graph is appropriate. By drawing a line or curve through the points,
you can clearly estimate what the “in between” values are likely to be, something you cannot
do as easily with a bar graph.
If the independent variable is discontinuous (i.e., there are no values between those tested),
then a bar graph would be appropriate. If you wanted to graph the average height of students
at each table in the lab (tables 1 through 6), the independent variable is the “specific table”.
Even though we label each table with a number, there are no “in between” values, there are
only tables 1, 2, 3, 4, 5 and 6, that’s it! So in this case a bar graph would be appropriate.
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When you’re ready to create a graph, you need to determine the range of values for each axis
and to scale and label each axis properly. Notice that the range of values on the axes of these
graphs are just a little bit larger than the range of values for each variable. As a result there is
little wasted space and the graph is well spread out and easy to interpret. It is also essential
that the units (e.g., grams or centimeters) for each axis be clearly indicated, and that each
interval on the scale represents the same quantity. By scaling each axis regularly and evenly,
each value plotted on the graph will be accurately represented in relation to the other values.
Conclusions
Once the data from an experiment are collected and presented, a conclusion is made with
regard to the original hypothesis. Based on the graph on the previous page it is clear that all
of the plants that received Compound X grew taller than the control plant which received no
Compound X. In fact, there is a general trend that increasing amounts of Compound X cause
the pea plant to grow taller (except for plants 5 and 6 which are very close).
These data clearly support the hypothesis, but they by no means prove it. In reality, you can
never prove a hypothesis with absolute certainty, you can only accumulate experimental data
that support it. However if you consistently produce experimental data that do not support a
hypothesis, you should discard it and come up with a new hypothesis to test.
Exercise 1B – Effect of distance on making baskets
In this exercise, you will design an experiment to determine the effect of distance on the
accuracy of shooting paper balls into a beaker (and also determine which person in your
group is the best shot!). Each student will attempt to throw small paper balls into a large
beaker at 3 different distances in addition to the control (which should be 0 cm, i.e., a slam
dunk!). You will measure each distance using the metric system and determine how many
attempts are made out of 10 total attempts at each distance.
1. State your hypothesis and identify your independent and dependent variables.
2. Place the large beaker on your lab table at each test distance and record how many
attempts out of 10 you make.
3. Graph the data for each member of your group on a single graph (use different curves
for each person) and answer the corresponding questions on your worksheet.
4. Conclude whether or not the data support your hypothesis and answer any other
associated questions on your worksheet.
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Part 2: The Metric System of Measurement
The English system of measurement is what we are all most familiar with (e.g., pounds,
inches, gallons), very few countries still use it to any significant degree (United States,
Myanmar and Liberia). Not even England still uses it! The problem is converting units
within the English system, which is rather awkward since there is no consistent pattern in the
relationship of one unit to another (12 inches per foot, 16 ounces per pound, four quarts per
gallon, etc…). Most countries in the world, including the entire scientific community, have
adopted a much easier system to work with called the Metric System of Measurement.
The advantage of the metric system of measurement is twofold: 1) there is a single, basic unit
for each type of measurement (meter, liter, gram, ºC) and 2) each basic unit can use prefixes
that are based on powers of 10 making conversions much easier. Once you learn the basic
units and the multiples of 10 associated with each prefix, you will have the entire system
mastered.
Basic Units of the Metric System
LENGTH - The basic unit of length in the metric system is the meter, abbreviated by
the single letter m. A meter was originally calculated to be one ten-millionth of the
distance from the north pole to the equator, and is ~3 inches longer than a yard.
VOLUME – The basic unit of volume in the metric system is the liter, abbreviated by
the single letter l or L. A liter is defined as the volume of a box that is 1/10 of a meter
on each side. A liter is just a little bit larger than a quart (1 liter = 1.057 quarts)
MASS – The basic unit of mass in the metric system is the gram, abbreviated by the
single letter g. A gram is defined as the mass of a volume of water that is 1/1000th of a
liter. [Note: 1/1000th of a liter = 1 milliliter = 1 cubic centimeter = 1 cm3 = 1 cc).
TEMPERATURE – The basic unit of temperature in the metric system is a degree
Celsius (ºC). Water freezes at 0 ºC and boils at 100 ºC.
Prefixes used in the Metric System
Unlike the English System, the metric system is based on the meter (m), liter (L or l) and
gram (g), and several prefixes that denote various multiples of these units. Specifically, each
basic unit can be modified with a prefix indicating a particular “multiple of 10” of that unit.
Here are the more commonly used prefixes and what they mean:
mega
(M)
106
kilo
(k)
105
104
103
BASIC
UNIT
102
101
100
deci
(d)
centi
(c)
milli
(m)
10-1
10-2
10-3
6
micro
(µ)
10-4
10-5
10-6
nano
(n)
10-7
10-8
10-9
Mega (M)
kilo (k)
no prefix
deci (d)
(c)
milli (m)
micro (µ)
nano (n)
=
=
=
=
=
=
=
=
106
103
100
10-1
10-2
10-3
10-6
10-9
=
=
=
=
=
=
=
=
1,000,000
1,000
1
1/10 (or 0.1) centi
1/100 (or 0.01)
1/1,000 (or 0.001)
1/1,000,000 (or 0.000001)
1/1,000,000,000 (or 0.000000001)
Here is how simple the metric system is using the basic units and the prefixes:
What is one thousandth of a meter? a millimeter (mm)
What is one one-millionth of a liter? a microliter (l)
What is 1,000 grams? a kilogram (kg)
Let us now examine these units more closely by using them to make actual measurements and
converting from one metric unit to another.
Exercise 2A – Measuring distance
1. Obtain a wooden meter stick. If you look on the back of the meter stick, one meter is
approximately 39 inches or about 3 inches longer than one yard (36 inches). Using the meter stick,
estimate the size of the laboratory by measuring its width and length to the nearest meter.
2. Observe that the meter is divided into 100 equal units called centimeters. A centimeter is about the
width of a small finger. Using the meter stick, estimate the dimensions of a regular piece of notebook
paper to the nearest centimeter.
3. How tall are you? Go over to the medical weight and height scale to measure how tall you are to
the nearest centimeter.
4. Next, obtain a small plastic metric rule. Observe that each centimeter is divided into 10 small units
called millimeters. A millimeter is about the thickness of a fingernail. Using the small plastic ruler,
estimate the diameter of a hole on a regular piece of notebook paper to the nearest millimeter.
What are some other real-world examples of metric units of length?
One micrometer (µm) is 1/1,000th the size of a millimeter or 1/1,000,000th of a meter. When
you observe a cheek cell under the microscope in a future lab, it is about 40 µm in diameter.
Typical bacteria are about 5-10 µm in diameter.
One nanometer (nm) is 1/1,000th the size of a micrometer or 1/1,000,000,000th of a meter.
Objects this small are far too tiny to observe even in a light microscope. If you line up five
water molecules side-by-side, the length would be about 1 nanometer.
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Exercise 2B – Measuring volume
1. Obtain a one liter (L or l) beaker. One liter is equal to 1,000 cubic centimeters (cc = cm3 =
milliliter = ml). Fill the beaker with one liter of water. To do this, add water until the meniscus (top
level of the water) reaches the 1 liter marker on the beaker. Pour the water into a 2 liter soda bottle.
Once again, fill the beaker with one liter of water by adding water until the meniscus reaches the 1
liter mark. Pour the water into the 2 liter soda bottle.
Once again, fill the beaker with one liter of water by adding water until the meniscus reaches the 1
liter mark. Over the sink, add the 1 liter of water to the 1 quart container provided. Notice that 1 liter
is just a little bit more than 1 quart. In fact, 1 liter = 1.057 quarts.
2. One way to measure the volume of a fluid in a laboratory is to use a graduated cylinder. Whereas
beakers are generally used to hold fluids, graduated cylinders are used to accurately measure volumes.
Obtain a 50 milliliter (ml) graduated cylinder. Fill the graduated cylinder with water until the
meniscus reaches the 50 ml mark. Add the water to a 1 liter (1,000 ml) beaker. Notice that 50 ml is
equal to 1/20th of a liter. Next, measure the fluid in the flask labeled “A” to the nearest 0.1 ml.
3. Pipettes are used to measure smaller liquid volumes whereas graduated cylinders are used to
measure larger volumes. Obtain a 10 ml glass pipette and attach it snugly to a pipette pump.
Notice whether or not the pipette is a delivery or blowout pipette. Blowout pipettes are designed for
measuring fluids all the way to the end of the pipette so that the liquid measured can be completely
“blown out” of the pipette. Delivery pipettes have a gap at the end of the pipette and are designed to
“deliver” the liquid down to the desired marking only. The remainder is discarded or returned to the
original container. (NOTE: blowing out a delivery pipette will give a wrong volume)
Using the roller on the pipette pump, gradually suck up some water until the meniscus reaches the 0
ml mark. Measure 10 ml of the water into the sink by rolling the roller in the opposite direction. Next,
measure the amount of fluid in the test tube labeled B to the nearest 0.1 ml using the 10 ml pipette.
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Exercise 2C – Measuring mass
A balance scale is used to measure the mass of a sample in grams (g).
1. Place an empty 50 ml graduated cylinder on the balance and determine its mass in grams.
2. Next, fill the graduated cylinder with 50 ml of water and measure the mass of both the cylinder
and the water. From this value subtract the mass of the cylinder to get the mass of the water.
By definition, one gram is the mass of exactly 1.0 ml of water, thus 50 ml of water has a mass of 50.0
grams. How far off was your measured mass from the true mass of 50 ml of water?
3. Next, take a large paper clip and place it on the balance and determine its mass in grams.
Exercise 2D – Measuring temperature
The metric unit for temperature is ºCelsius (ºC). Water freezes at 0 ºC and boils at 100 ºC. Note that
this is much easier to remember than the corresponding values of 32 ºF and 212 ºF.
1. Use a thermometer to measure the following in degrees Celsius:
A) the ambient temperature of the lab B) a bucket of ice water C) a beaker of boiling water
2. Convert the temperatures on your worksheet from ºC to ºF or ºF to ºC with the following formulas:
ºC = 5/9 x (ºF - 32)
ºF = (9/5 x ºC) + 32
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Converting Units within the Metric System
Once you are familiar with the units and prefixes in the metric system, converting from one
unit to another requires two simple steps:
1) divide the value associated with the prefix of the original unit by the prefix of the
unit you are converting to
2) multiply this value by the number in front of the original unit
To illustrate this let’s look at an example:
2.4 kg =
In this case you’re converting from kilograms to milligrams. Since the prefix kilo- refers to
1000 and the prefix milli- refers to 1/1000 or 0.001 (see page 7), divide 1000 by 0.001. This
gives a value of 1,000,000 which is multiplied by 2.4 to get the mass in milligrams:
2.4 kg = 2.4 x 1,000,000 mg = 2,400,000 mg
You may find it simpler to associate each metric prefix with an exponential number. With
this approach kilo- refers to 103 and milli- refers to 10-3, so 103/10-3 equals 106 (when
dividing exponential numbers simply subtract the first exponent minus the second), and thus:
2.4 kg = 2.4 x 106 mg = 2,400,000 mg
mg
Whether or not you represent your answer as an exponential number is up to you, either way
the values are the same. To ensure that you’ve done the problem correctly, remember that
any given distance, mass or volume should contain more of a smaller unit and less of a
larger unit. This is simply common sense if you think about it. As you can see in the
example above, there are a lot more of the smaller milligrams than there are the larger
kilograms, even though both represent the exact same mass. So each time you do a metric
conversion look at your answer to be sure that you have more of the smaller unit and less of
the larger unit.
One more thing to remember is that a basic unit without a prefix (m, g or l) is one or 100 of
that unit. Here are a couple more examples just to be sure everything is clear:
643 m =
km
50 ml =
l
1 divided by 1000 (kilo-) = 0.001 x 643 = 0.643 km
-3
0
-3
10 (milli-) divided by 10 = 10 x 50 = 5.0 x 10-2 l
Exercise 2E – Metric Conversions
Complete the metric conversions on your worksheet.
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LABORATORY 1 WORKSHEET
Name
Section
Exercise 1A – Good vs bad hypotheses
Circle good or bad for each hypothesis, and underline any terms that make a hypothesis bad:
1. Students who own laptops have higher GPAs.
Good or
Bad
2. Murders occur more often during a full moon.
Good or
Bad
3. Cats are happier when you pet them.
Good or Bad
4. Orangutans are smarter than gorillas.
Good or
Bad
5. Sea level will be higher in 100 years than it is today.
Good or
Bad
Exercise 1B – Paper basketball experiment
State your hypothesis:
In the table below, record the number of shots made at each distance (out of 10) for each person:
Name
0 cm
cm
cm
cm
Graph the data for each member of your group below (use a different curve for each person):
What is your control in this experiment?
What is the independent variable?
What is the dependent variable?
State your conclusion addressing whether or not the data support your original hypothesis:
Exercise 2A – Measurement of distance
Laboratory width:
m
Calculate approximate area: width
Paper width:
m
cm
Paper hole diameter:
x
length
m =
Paper length:
Calculate approximate area: width
Your height:
Laboratory length:
cm
x
length
cm =
m
Indicate which metric unit of length you would use to measure the following:
length of a fork
width of a plant cell
size of a small pea
length of your car
height of a refrigerator
distance to the beach
diameter of an apple
size of a dust particle
Exercise 2B – Measurement of volume
Volume of fluid in Beaker A =
Volume of fluid in Test Tube B =
ml
ml
m2
cm
mm
cm, which is equal to
m
cm2
Exercise 2C – Measurement of mass
Mass of Graduated Cylinder =
g
Mass of Graduated Cylinder with 50 ml of water =
Mass of 50 ml of water:
g
g
Difference between calculated and actual mass of 50 ml of water:
Mass of 1 ml of water based on your measurements:
Mass of Large Paper Clip =
g/50 ml =
g/ml
g
Exercise 2D – Measurement of temperature
Ambient temperature in lab
ºC
ice water
ºC
boiling water
Convert the following temperatures using the formulas on page 10 of the lab exercises:
Mild temperature:
72 ºF =
ºC
10 ºC =
ºF
Cold day
Body temperature
98.6 ºF =
ºC
34 ºC =
ºF
Very hot day
Exercise 2E – Metric conversions
_ ºC
Convert the following measurements to the indicated unit:
335.9 g =
kg
0.00939 µl =
ml
456.82 ng =
kilobytes
8 megabase pairs (mbp) =
ºC = 100 ºF µg
20 megabytes =
95 ºC =
ºF
m = 0.0886 km
kg = 89 mg
dl = 900.5 cl
µm = 0.37 mm
kbp
mm = 11.5 nm
Speed Challenge
Materials: stopwatch
meter stick
tape or masking tape
marker
Procedures: Step 1: Gather your materials Step 2: Find a spot in the hallway and measure off a 10 meter race track. Use 3 pieces of tape to mark the beginning, middle and end of your track. Step 3: Have each person from your team take turns WALKING the race track (from 0m to 10m) while the other team members use the stopwatch to accurately time the trip. Step 4: Record the data for your own walk in your own data table. Step 5. Repeat steps 3 and 4 with HOPPING, WALKING BACKWARDS, and SPEED-­‐ WALKING*. Record all data for your own walks in your data table. Step 6: Clean up: All tape must be cleared off the floor in the hall way. Your teacher will ask to see the tape is taken up. Return the timer, meter stick and markers to your teacher. Safety: Be careful. Your shoes should be appropriate for lab. Clear the hallways of obstructions or objects before doing the lab. Courtesy: Other students are in class learning. We do not want to interfere with their learning. Be considerate and as quiet as possible while taking data so we may do future assignments out of the classroom. *Definition of Speed Walking: SPEED WALKING IS GOING AS FAST AS YOU CAN WITHOUT JOGGING OR RUNNING. THERE SHOULD NOT BE ANY RUNNING IN THE HALL WAY.* Data Table Task Walking Hopping Walking Backwards Speed-­‐Walking Distance (y) 10m 10m 10m 10m Time (seconds) (x) Use your data table to complete the following line-­‐graph. Remember to title your graph, label your x and y axes, and provide an accurate scale. Use a different color for each task (your graph should have 4 separate lines) and provide a key. Analysis: Look at your graph. Which task produced the steepest line? Which task produced the least steep line? What conclusions, if any, can you make about the steepness of a line on a distance/time graph? Calculations Use your graph to calculate the speed of each task. (Hint: the speed is the same as the SLOPE of the line) Label your answers with m/s. Walking: Hopping: Walking Backwards: Speed-­‐Walking: Questions: Which task had the fastest speed? How do you know? Which task had the slowest speed? How do you know? Conclusion: In at least 3 complete sentences, tell how your speed is related to the line on the graph you drew. Use your data to support your response (there should be numbers in your response).
Calculating Speed from a Graph Directions: Use the story to draw a graph. Then use the graph to calculate the speed. Don’t forget to label your axes and correctly scale your graphs. 1) A car is traveling down the road. It drove for 50 seconds and in that time it traveled 100 meters. What is the speed of the car? 2) If an ant crawls 1 meter in 25 seconds, what is the ant’s speed? 3) a) Three elephants are standing on a very very strong bridge. The bridge happens to have marks at every meter along the way (almost like it was meant for setting up a physics problem). Elephant #1 is standing at 4m and starts walking. He walks for 30 seconds and after 30 seconds, the elephant is at the place on the bridge marked 64 meters. What is Elephant #1’s speed? b)If Elephant #2 started at 3m and it took him 90 seconds to walk to meter mark 93m, what was Elephant #2’s speed? c) Elephant #3 was a track star in his day, so he has been standing on the 5m mark. He starts running, and 10 seconds later, he is at the 25m mark. What was Elephant #3’s speed? 4) A beetle has been walking down a sidewalk. He started at 3:15 in the afternoon, and by 3:20 he had made it 4 meters. What is the beetles speed in m/s? (Hint: there are 60 seconds in one minute) Distance vs. Time Graphs Directions: Draw the graph of distance over time. Be careful, do not confuse the distance/time graph with a graph of the terrain. 1) I was walking to the bus stop when I suddenly saw the bus coming. I ran as fast as I could towards the stop, but the bus moved off before I got there. I walked slowly the rest of the way to the stop and sat, waiting for the next bus. 1 2 3 4 5 6 2) Mr. Rose went down the street on his skateboard. At the end of the street he ran into the curb and came to a sudden stop. 3) Mrs. Brevetti set off for Cheyenne one morning. When she was half way there, she remembered she had left some important teacher things at home, so she went back to get them. Then, she realized she was going to be late, so she hurried all the way back to school. 4) Billy went swimming after school. He swam slowly up and down the pool for 4 laps, and then he did two laps at top speed (one pool length=one lap). 5) Mrs. Antkowiak is learning to ski. She waited in the tow-­‐rope line at the bottom of the hill for 5 minutes; rode up the lift for 3 minutes, and then set off downhill. She skied extra slowly down the hill, so she wouldn’t lose control and it took her 5 minutes to get down the hill. Once at the bottom, she waited for her husband (who skis even more slowly) to join her. 6) Anne and Barbara raced one another to the opposite side of the parking lot and back. Barbara got a good start and kept up a steady pace all the way. Ann was late getting off the curb, but she ran faster than Barbara, and passed her before they reached the far side. About halfway back to the starting point, Ann stumbled and fell. She got up again quickly, but she had hurt her ankle and, as she limped on, Barbara passed her and won the race. 7) Cragen and Huckerby went on the Ferris Wheel at the fair. The wheel started up slowly, and once it got to the top it came down a little bit faster. It started up again, and when the puppies were at the top, it stopped to let people on. 7 Directions: Look at the distance vs. time graph and come up with a plausible story to explain its movement. 1. 2. 3. 4. Calculating Speed in m/s 1) A car is traveling down the road. It drove for 50 seconds and in that time it traveled 100 meters. What is the speed of the car? 2) If an ant crawls 1 meter in 25 seconds, what is the ant’s speed? 3) a) Three elephants are standing on a very very strong bridge. The bridge happens to have marks at every meter along the way (almost like it was meant for setting up a physics problem). Elephant #1 is standing at 4m and starts walking. He walks for 30 seconds and after 30 seconds, the elephant is at the place on the bridge marked 64 meters. What is Elephant #1’s speed? b) If Elephant #2 started at 3m and it took him 90 seconds to walk to meter mark 93m, what was Elephant #2’s speed? c) Elephant #3 was a track star in his day, so he has been standing on the 5m mark. He starts running, and 10 seconds later, he is at the 25m mark. What was Elephant #3’s speed? d) Out of Elephants 1, 2, and 3; which elephant was the FASTEST? Which elephant was the SLOWEST? Explain how you know. 4) a) A beetle has been walking down a sidewalk. He started at 3:15 in the afternoon, and by 3:20 he had made it 4 meters. What is the beetles speed in m/s? (Hint: there are 60 seconds in one minute) b) A boy has also been walking down a sidewalk. He, too, started at 3:15 in the afternoon. However, by 3:20 the boy had made it 200 meters. What was the boy’s speed in m/s? c) Who was walking FASTER? The boy or the beetle? How do you know? The graph to the left is a graph of
distance traveled over time. Use the
graph to answer the following
questions.
1) Calculate the speed from A to B.
2) Calculate the speed from B to C.
3) Calculate the speed from C to D.
The graph to the right is a graph of distance
traveled over time. Use the graph to answer
the following questions.
4) Calculate the speed from A to B.
5) Calculate the speed from B to C.
6) Calculate the speed from C to D.
7) Between which letters is the FASTEST
speed?
8) What is wrong with the distance/time graph to the left? What happens when velocity changes? Books to make ramp Materials: 2 meter sticks, marble, books (4 science books), masking tape, 2 stop watches, 3 calculators Diagram Finish Line 1.5 meters from the edge of the meter sticks Book to stop marble Distance from the bottom of the meter stick is 1.5 meters Predict: What will happen to the marble as it leaves the ramp and rolls toward the backstop? Marble Tape joins these two meter sticks together from the underside Procedure 1. Make a ramp by laying two meter sticks side by side. Leave a small gap between the meter sticks. 2. Use masking tape (as shown by your teacher) to join the meter sticks. The marble should be able to roll freely along the groove. 3. Set up your ramp along the ground, preferably on carpet. Raise one end of the ramp on top of the books, the other end of the ramp should remain on the ground. 4. Make a line by putting a piece of tape 1.5m from the bottom of the ramp. Place a backstop at the 1.5m mark. Test you ramp by releasing the marble from the top of the ramp. Make sure that the marble rolls freely. Do not push the marble. 5. Release the marble and measure the time it takes for it to roll from the release point to the end of the ramp. ( You will do this 3 times and get an average)Make sure and record your observations in the table given. 6. Release the marble again from the same point, and record the time it takes the marble to roll from the end of the ramp to the finish line. (You will do this 3 times and get an average) Record this time. Draw the set up of your experiment below and label everything ! 37 Top of Ramp to Bottom of Ramp Distance=1 m Time #1 (s) (top to b ottom of Trial 1 2 3 Total Average Velocity #1 (m/s) Data: Bottom of Ramp to Backstop Distance=1.5m (Use Distance over average time to calculate velocity) Time #2 (s) Trial 1 2 3 Total Average Velocity #2 (m/s) (bottom of ramp (direction needed) Analysis (use complete sentences) 1. Are Velocity #1 and Velocity #2 the same? 2. Why do you think this might be? 3. Compare Velocity #1 to Velocity #2. What are some possible reasons that the numbers are related to each other this way? 4. Do your calculated velocities match your prediction from the beginning of the lab? Explain. 5. At what point during your investigation did you notice the marble’s velocity changing? 38 Synthesis (use complete sentences) 1. When Velocity changes (even just a little bit), it is called acceleration. In what ways did your velocity change? 2. Did your marble “speed up” or “slow down” based on your observations? Explain. 3. Did your marble “speed up” or “slow down” based on your Velocity Calculations? Explain how you know. 4. Predict what you think would happen if the marble was moving over t ile instead of carpet. How would that affect the marble’s acceleration? Explain. Conclusion Write a paragraph, using numbers from your data, that describes what we did in this lab, what you observed happen, and how this relates to the numbers you calculated and the change in Velocity. 39 40 What happens when velocity changes? (follow up Questions) Using your lab results from yesterday, complete the following questions. 1. Acceleration is when velocity changes. Yesterday, you observed the velocity of your marble changing as it rolled off the ramp and onto the carpet. You used the distance the marble traveled over the time it took to travel that distance to calculate two different velocities. What was your velocity #1? What was your velocity #2? What was your time #2? 2. Acceleration can actually be calculated as a numerical value. Put your velocities into the following equation to calculate the acceleration of your marble. The unit for acceleration is m/s2. Calculate: Velocity #2 – Velocity #1 Work: Average Time #2 It is VERY important that you do not mix up the order of the velocities. It is OKAY if your acceleration is a small decimal or even a negative number! 3. What would it mean if your acceleration turned out to be a positive number? 4. What would it mean if your acceleration turned out to be a negative number? 5. What would it mean if your acceleration turned out to be zero? 41 Conclusion Paragraph 6. Which of the above three scenarios best matches what you calculated? Does it match what you observed happening to your marble yesterday? If yes, describe what this means. If no, please give several reasons why this contradiction could have occurred. 42 Acceleration Practice Problems 1. A roller coaster car rapidly picks up speed as it rolls down a hlope. As it starts down the slope, its speed is 4 m/s. But 3 seconds later, at the bottom of the slope, its speed is 22 m/s. What is the car’s acceleration? 2. A cyclist accelerates from 0 m/s to 8 m/s in 3 seconds. What is his acceleration? b) A car accelerates from 0 m/s to 30 m/s in 8 seconds. What was its acceleration? 4. A lizard accelerates from 2 m/s to 10m/s in 4 seconds. What is the lizard’s acceleration? 5. A bicyclist is riding in a hilly area. She approaches a hill and when she arrives at the bottom of the hill she is traveloing at a speed of 15 m/s. After 1 minute, she arrives at the top of the hill and her speed is now 7 m/s. What was her acceleration up the hill? 6. Who has the greater acceleration rate? A runner who can go from 0 m/s to 12 m/s in 10 seconds, or a runner who can go from 5 m/s to 10 m/s in 5 seconds? c) Who had the higher rate of acceleration? ****CHALLENGE QUESTION**** 3. A car advertisement states that a certain car can accelerate from rest to 70km/h in 7 seconds. Find the car’s acceleration in m/s. 7. If a Ferrari, with an initial velocity of 10 m/s, accelerates at a rate of 50 m/s2, for 3 seconds, what was his ending velocity? Formula: 43 Crash Test Dummies Lab 8th Grade Science There are 5 different parts to the following lab. Do them each ONE AT A TIME. Make sure you copy the QUESTION, your PREDICTION, and YOUR DRAWING for each part. You should end up with FIVE fully-­‐labeled diagrams. Part I: Question: What will happen to a lump of clay on top of a car if the car crashes into a textbook? Prediction: Procedures: 1. Shape a ball out of clay about the size of a marble. 2. Place a textbook 100 cm away from your car. 3. Put your ball of clay on top of your car. 4. Give your car with the clay a soft push so that it will drive to the textbook and CRASH. 5. Draw (in your notebook) what happened to your clay “dummy”. a. Title your picture “SOFT PUSH” b. Label the following in your picture i. Car ii. CRASH wall iii. Direction of car iv. Direction/motion of clay BEFORE crash v. Direction/motion of clay AFTER crash Part II: Question: What will happen to the lump of clay on top of the car if the car is given a medium push? Prediction: Procedures: 1. Re-­‐shape clay ball and re-­‐attach it to the top of the car. 2. Give your car with the clay a medium push so that it will drive into the textbook and CRASH. 3. Draw (in your notebook) what happened to your clay “dummy”. a. Title your picture “MEDIUM PUSH” b. Label the following in your picture i. Car ii. CRASH wall iii. Direction of car iv. Direction/motion of clay BEFORE crash v. Direction/motion of clay AFTER crash Part III: Question: What will happen to the lump of clay on top of the car if the car is given a hard push? Prediction: 44 Procedures: 1. Re-­‐shape clay ball and re-­‐attach it to the top of the car. 2. Give your car with the clay a hard push so that it will drive into the textbook and CRASH. 3. Draw (in your notebook) what happened to your clay “dummy”. a. Title your picture “HARD PUSH” b. Label the following in your picture vi. Car vii. CRASH wall viii. Direction of car ix. Direction/motion of clay BEFORE crash x. Direction/motion of clay AFTER crash Part IV: Question: What will happen to the lump of clay on top of the car if the car receives a rear-­‐end collision by another car? Prediction: Procedures: 1. Re-­‐shape clay ball and re-­‐attach it to the top of the car. 2. Working with the lab table next to you, one car will cause the rear-­‐end collision (NO CLAY BALL) and the other car will receive the collision (WITH CLAY BALL). 3. Draw (in your notebook) what happened to your clay “dummy”. a. Title your picture “REAR-­‐END COLLISION” b. Label the following in your picture xi. Car xii. CRASH CAR xiii. Direction of car xiv. Direction of CRASH CAR xv. Direction/motion of clay BEFORE crash xvi. Direction/motion of clay AFTER crash Part V: Question: What will happen to the lump of clay on top of the car if the car receives a side-­‐impact collision by another car? Prediction: Procedures: 1. Re-­‐shape clay ball and re-­‐attach it to the top of the car. 2. Working with the lab table next to you, one car will cause the rear-­‐end collision (NO CLAY BALL) and the other car will receive the collision (WITH CLAY BALL). 3. Draw (in your notebook) what happened to your clay “dummy”. a. Title your picture “SIDE-­‐IMPACT COLLISION” b. Label the following in your picture xvii. Car xviii. CRASH CAR xix. Direction of car xx. Direction of CRASH CAR xxi. Direction/motion of clay BEFORE crash xxii. Direction/motion of clay AFTER crash 45 Application Questions: Answer these questions in complete sentences. You may discuss the answers with your group. 1. How does the force of your push compare with the speed you observed the car travel? 2. Discuss what happens to the dummy in FRONT-­‐ end collisions. 3. Did the distance the car was pushed have anything to do with the distance the clay traveled? What about the strength of the push? Explain. 4. Discuss what happens when the car is hit from behind. Why does this happen? 5. What injury would be common in REAR-­‐END collisions? 6. What is the clay resisting in each of the scenarios? 7. How does this lab apply to Newton’s first law of motion? 8. Why is it important to wear seatbelts? Use specific examples from your drawings to support your answer. 46 9. What are some ways that car companies are preventing injuries from head-­‐on, rear-­‐end and side collisions? 10. What happens to the force of the moving car once it hits the books? 11. Which would be WORSE: being struck by a SEMI-­‐TRUCK or a TOYOTA PRIUS? Explain your answer in two complete sentences. 12. What are the VARIABLES in this lab ? Independent _Dependent 13. Restate Newton’s First Law 14. Inertia 47 48 49 50 51 52 Net Force Practice Pages 53 54
Balloon Rockets th 8 Grade Science Question: How does mass affect the velocity of a balloon? Prediction: I think that the mass will …. Materials: balloon, straw, tape, string, index card, paper clips Procedure: 1. 2. 3. 4. 5. 6. 7. 8. 9. Attach a straw to the very top of an index card. Thread the string through the straw. Blow up the balloon and attach it to the card. DO NOT TIE THE BALLOON OFF! Pinch the end off with your fingers! Move the rocket assembly to the edge of the tape. Have 2 group members each hold one end of the string. Simultaneously (together) released end of the balloon while starting the timer. Stop the timer when the rocket assembly reaches the end of the strong. Record your time and calculate the speed of the balloon. Attach large paperclips and complete the above steps again for 4 and 7 paperclips. Name your CONTROLLED VARIABLES in this activity What was the dependent variable? Data: Zero Paper Clips Trial # What was the independent variable? Distance (m) 1 2 3 2m 2m Time (s) Velocity (m/s) Average Velocity 2m Remember: V= Distance time m/s 55
Question: What will happen to the rocket assembly when MASS/PAPER CLIPS are added? Prediction: I think that added mass will….. Data: 4 paper clips added Trial 3 2m 2m V= Distance time m/s Data: 7 paper clips added Velocity (m/s) Remember: 2 Trial # Time (s) Average Velocity 2m 1 Distance (m) Distance (m) 1 2 3 Average Velocity Time (s) Velocity (m/s) 2m Remember: 2m V= Distance time 2m m/s Analysis Questions: 1. As mass was added, did the velocity INCREASE OR DECREASE? Use your data to support your answer. 2. Newton’s second law states that F= mass * acceleration. In this experiment, what part of your rocket represents the FORCE? 3. Did you keep the force constant? 4. As mass was added to the assembly, how did it affect the acceleration? 5. Name two possible sources of error in this activity. 6. If you were to vary the size of the balloon what part of the equation (F= ma) will you be changing? Explain
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Spring Scale Lab Newton’s 2nd Law 8th Grade Science Objective: Use Newton’s 2nd Law of Motion to calculate acceleration of several masses. Materials: Spring Scale (blue or yellow) 1000g mass (yellow scale ONLY) 500g mass (yellow scale ONLY) 200g mass 100g mass 50g mass 20g mass 10g mass Procedure: 1. In this lab, you will be using a spring scale to measure the FORCE of several different masses. Make sure to familiarize yourself with the value of the increments on the spring scale. You are expected to record your results with the correct decimal units. 2. Copy the following data table into your Science Notebook. 3. In your data table, copy down the mass of the mass at your table in front of you (each table should have a different mass) 4. Have a partner hold the spring scale still about .5 meters above the table surface. The two of you will need to read the scale carefully. 5. Carefully, while still holding the bottom of the mass, hang the hook from the spring scale. Slowly lower your hand so that the mass is hanging on its own. 6. Record the CORRECT number of NEWTONS for the mass in your data table. 7. Repeat steps 2-­‐5 until you have found the force for every mass in the data table. Data: Mass (g) 1000g Force (N) 500g 100g 50g 20g 10g 57
Newton’s 2nd Law 8th Grade Science Calculations part 1: 1. In order to use Newton’s 2nd Law, you will need to convert all of your masses to kilograms. Use the following table to do so: Mass (g) Mass (kg) 1000g 500g 100g 50g 20g 10g 2. Re-­‐copy your new data into the table below: Force (N) Mass (kg) 3. Newton’s 2nd Law states that Force is equal to mass times acceleration. This means that Force divided by mass is equal to acceleration. Use this information to calculate the acceleration of each mass. Force (N) Mass (kg) ACCELERATION (m/s2) Force/Mass 58
Reflection Questions: 1. Define Acceleration: 2. Based on the definition of acceleration, did you notice the masses accelerating? 3. Define Force: 4. Where did the “push” or “pull” come from that caused there to be FORCE on the masses? 5. Discuss what acceleration you are calculating. 6. In your data, you calculated several accelerations. What did you notice about the values you calculated? 7. Predict what the FORCE would be for a mass of 2000g. EXPLAIN how you got your answer. 8. Predict what the MASS would be of something exerting a force of 45N on a spring scale. EXPLAIN how you got your answer. 9. Why might it be useful to know this constant value of acceleration? Think of a real-­‐life scenario where this information could be useful. 59
New to n ’s 2 nd Law Practice Problems F=MA WORKSHEET 2 1. How much force is required to accelerate a 2 kg mass at 3 m/s ? 2 2. Given a force of 100 N and an acceleration of 10 m/s , what is the mass? 3. What is the acceleration of a 10 kg mass pushed by a 5 N force? 2 4. Given a force of 88 N and an acceleration of 4 m/s , what is the mass? 2 5. How much force is required to accelerate a 12 kg mass at 5 m/s ? 2 6. Given a force of 10 N and an acceleration of 5 m/s , what is the mass? 2 7. How much force is required to accelerate a 5 kg mass at 20 m/s ? 8. What is the acceleration of a 5 kg mass pushed by a 10 N force? 2 9. Given a force of 56 N and an acceleration of 7 m/s , what is the mass? 2 10. How much force is required to accelerate an 8 kg mass at 5 m/s ? 11. What is the acceleration of a 24 kg mass pushed by a 6 N force? 12. What is the acceleration of a 25 kg mass pushed by a 10 N force? 2 13. Given a force of 100 N and an acceleration of 5 m/s , what is the mass? 2 14. How much force is required to accelerate a 50 kg mass at 2 m/s ? 15. What is the acceleration of an 18 kg mass pushed by a 9 N force? 60
Performance Assessment Newton’s Laws Physics Phun Objective: To demonstrate one of Newton's laws of motion To speak effectively using appropriate vocabulary to explain a science concept Context: Small cooperative groups Materials: Varies with each group. Students may bring items from home with prior approval from parents and teacher. Procedure: 1. Plan a group presentation on one of Newton's three laws of motion. You may act it out or show it using props or other materials. Each person in the group must participate in your presentation. 2. Follow the following format: o
o
o
o
State the law of motion. Demonstrate this law or act it out. Explain how your presentation shows that particular law. Use science vocabulary words whenever appropriate. 3. Remember to work cooperatively in your group. Plan and practice together so that each person knows what to do in advance. 4. Speak loudly and clearly so that you can be easily understood. 5. Have Phun! 61
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Investigate Momentum (p. 66 in Textbook) Purpose: To observe what happens when objects collide Materials: 2 rulers 8 marbles Procedure: 1. Set up two parallel rulers separated by one centimeter. Place a line of five marbles, each touching the next, in the groove between the rulers. 2. Roll a marble down the groove so that it collides with the line of marbles and observe the results. 3. Repeat your experiment by rolling two and then three marbles at the line of marbles. Observe the results. Apparatus: Draw and label your lab setup. Draw a before and after picture, after completing your lab, also. Questions: 1. What did you observe when you rolled the marbles? 2. Why do you think the marbles moved the way they did? 64
Fabulous Friction At the main station or table your teacher has provided you various materials to design/create, perform and report your results on FRICTION. It is your task as a lab group to decide what materials you are planning to use, how you are going to use the materials and the best way to set up your experiment to answer your question. After you have completed the experiment you will each write a lab report on your experiment and share your results with the class. Consider what you have learned in science (experimental design) and use your best science practices. Check out your experimental design planning sheet, district lab report format, and the student check list that follow this assignment. Before beginning your inquiry into friction, discuss what you already know about friction as a group and fill out the following “T” chart. Then research friction by using your text and answer these questions. These will help you ask your testable question. What we know about friction Questions about friction What is friction? Why does it happen? What is affected when friction occurs on surfaces? How do you increase or decrease friction? Where does friction occur? Can it happen in liquids, air, with solids? What are examples of friction in daily life? 65
What materials are you using for your experiment? Testable question (include independent and dependent variable-­‐underline each and label) Hypothesis What factors are you going to control to prevent error/mistakes? Procedure-­‐write the procedures for your experiment in 1., 2., 3., format using complete sentences with specific detail. Other students should be able to take your procedures and perform this lab using the procedures and materials available on the lab station. 66
Record your Data-­‐ make your own data table to record your findings. Be sure to use units. (Include tables, drawings, labeled sketches etc) You may use the graph paper that follows or you may copy and paste your own graph paper into this lab notebook. 67
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Analyze Your Data: Discuss your findings. What did you see happen? Why did it happen? Explain in complete sentences Did your data support your hypothesis? Why or why not? Explain in complete sentences. Did anything unexpected happen? What were some problems that you had in your experiment? (Explain in at least 5 complete sentences) 69
Conclusion: What happened? Why did it happen? (Explain in at least 5 complete sentences) 70
PICK ONE TO DO: Extension 1: In daily life, sports and recreational activities you may want to decrease or increase the amount of friction present. Using what you have learned about surface type and force on the surface list at least 5 activities where INCREASING the amount of friction is helpful and 5 activities in which it is advantageous to reduce the amount of friction. (Ex: gymnasts use chalk on their hands to reduce friction between their hands and uneven bars; cleats help football players have better traction when running….) Include this in your lab report at the end of the lab report. Extension 2: Create a mini news article on a piece of white paper (by computer or by hand) for a recreation or sports magazine about how friction plays a role in a sport of your choice. Include a colorful, creative picture of the sport in action and describe in a PARAGRAPH of 4-­‐6 complete sentences on HOW friction affects a player’s performance in that sport. Talk to your PE teacher or coach for ideas. Be ready to share with the class. Include this in your lab report at the end of the lab report. Requirements: Format of Lab Report 1. Must be typed at home or at school on your own time 2. Double spaced (Arial, New Times Roman, Calibri Font) 3. Complete Sentences with correct grammar and spelling (spell check and read) 4. Follow District Lab Report Format 5. Length: 2 pages in length 6. Paragraph size: 4-­‐7 complete sentences 7. You may design the experiment TOGETHER but you must write your own lab report. Each student must do his/her own work. You may not do one lab report and copy for all of your members. Must be your own work, in your own words. Failure to follow this requirement will result in redoing the entire assignment or a zero. 8. Include data tables, graphs, or pictures when appropriate. These must have correct labels, titles and units. Pictures may be used only if they show your experimental design and outcomes. How to turn in the lab report 1. Title page: Name, hour, testable question, group members 2. Lab Report: following district guidelines 3. Extension 1 or 2 4. Staple together ATTENTION: Use the student check list (and all the resources) during the development of your experiment to help you make sure that you are including specific components. Each student should be filling out this information in his/her lab notebook during class so that when you are writing your lab report you will have the necessary information to complete your lab report. You may work together to design your lab but you must do your own lab report. 71
Basic Process Team Names: Student Checklist
Describe specifically how your experiment allows you to use each skill
in the spaces below
Adapted from Mark
Goddard 2003
Uses five senses to observe; observes using tools (lens, etc.); identifies properties of an object; uses numbers to describe observations; notes changes in objects; realizes that observation enhances understanding. Observation Identifies similarities and differences in properties; identifies properties for sorting; classifies objects or attributes into groups; forms subgroups; has logical rationale for sorting; understands characteristics define sorting systems Classification Describes accurately using appropriate vocabulary; asks relevant questions; verbalizes thinking; shares views with others; constructs other means to communicate (reports, media, graphs, etc.) Communication Uses non-­‐standard ways as well as traditional ways to measure; selects appropriate measuring tools; uses tools with precision (i.e., to 10ths in metric); compares and orders objects by weight, length, volume and/or time Measurement Performs simple predictions based on inferences; recognizes and extends patterns; shows reasoning in defending predictions; able to blend events, patterns, and data to form ideas of what may happen in the future Prediction Score 0-­‐4 Rate
1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 72
Adapted from Mark
Goddard 2003
Able to identify variables within an experiment that are to be held constant and those that are to be manipulated; understand the difference between single and multiple variable manipulation Controlling Variables Interpreting Data Integrated Process Performs simple predictions based on inferences; recognizes and extends patterns; shows reasoning in defending predictions; able to blend events, patterns, and data to form ideas of what may happen in the future Rate Score 0-­‐4 Able to visualize the procedures that may be necessary to answer question and plan the appropriate data collection operation; includes a plan to organize data; uses organized, sequential plans to test a hypothesis Designing Experiments Uses all appropriate information to form inferences and is able to distinguish non-­‐essential information; develops inferences (ideas) based on observations; able to defend inferences reasonably and logically Able to explain relationships between observed actions to explain phenomena; uses events to describe how something works or doesn't work; is able to find alternative actions from evaluating what doesn't work Defining Operational 1 2 3 4 1 2 3 4 1 2 3 4 Inferring 1 2 3 4 1 2 3 4 73
Student Name _hr Basic Process Uses five senses to observe; observes using tools (lens, etc.); identifies properties of an object; uses numbers to describe observations; notes changes in objects; realizes that observation enhances understanding. Identifies similarities and differences in properties; identifies properties for sorting; classifies objects or attributes into groups; forms subgroups; has logical rationale for sorting; understands characteristics define sorting systems Describes accurately using appropriate vocabulary; asks relevant questions; verbalizes thinking; shares views with others; constructs other means to communicate (reports, media, graphs, etc.) Uses non-­‐standard ways as well as traditional ways to measure; selects appropriate measuring tools; uses tools with precision (i.e., to 10ths in metric); compares and orders objects by weight, length, volume and/or time Performs simple predictions based on inferences; recognizes and extends patterns; shows reasoning in defending predictions; able to blend events, patterns, and data to form ideas of what may happen in the future Observation Classification Communication Measuring Prediction Integrated Processes Able to find meaning or patterns with accuracy between sets of information and use that meaning to construct inferences, predictions, and hypothesis; able to identify a single pattern among objects within an experiment Able to identify variables within an experiment that are to be held constant and those that are to be manipulated; understand the difference between single and multiple variable manipulation Able to visualize the procedures that may be necessary to answer question and plan the appropriate data collection operation; includes a plan to organize data; uses organized, sequential plans to test a hypothesis Uses all appropriate information to form inferences and is able to distinguish non-­‐essential information; develops inferences (ideas) based on observations; able to defend inferences reasonably and logically Interpreting Data Controlling Variables Designing Experiments Inferring Research and Writing General Format EXTENSION Score 0-­‐4 Teacher Rubric- Description
Adapted from Mark
Goddard 2003
date received_ Missing-­‐0 Research not done for experiment. Shows no understanding of concepts and does not use prior knowledge. 2-­‐1 Below Proficient Incomplete information on topic, poor organization, many misspellings, poor punctuation and lack of complete sentences. Does not show a solid expression of concepts and does not incorporate prior knowledge. 3-­‐ Proficient – solid expression of concepts, a broad range of information written very well. Incorporates prior knowledge. Complete sentences used with 1-­‐2 spelling and/or grammar mistakes 4 Exemplary -­‐ thorough understanding and expression of concepts, information comple te, incorporates prior knowledge, and written creatively and technically. 0 spelling or grammar mistakes. Complete sentences use d. 0-­‐Experiment 1-­‐Experiment does not 2 Fair-­‐The experiment meets 3-­‐ Good-­‐The 4-­‐Outstanding-­‐ th e not completed, accomplish what was asked; most of the criteria and does experiment experiment meet s all did not contains errors and is of not contain gross errors or completely meets the criteria, exceeds complete the poor quality significant omissions expectations expectations and assignment, or described by the shows additional did not show criteria effort comprehension 4-­‐ Student did an outstanding job. Meets all criteria and exceeds expectations in length, neatness and shows additional effort. 3-­‐ Student met the expectation for the format of the lab report described by the criteria. 2-­‐ Student attempted to meet the expectations but had minor omissions or errors in the format of the lab report. 1-­‐Student did not accomplish what was asked; format not followed; major omissions or errors in the format of the lab report. 0-­‐Student did not attempt to follow format, none of the criteria was followed in lab report. 4-­‐ Student did an outstanding job on extension. Meets all criteria and exceeds expectations for assignment. Shows additional effort. 3-­‐ Student met the expectation for extension described by the criteria. 2-­‐ Student attempted the extension but there were missing pieces of information and or incorrect reasoning 1-­‐Student did not accomplish what was asked; contains major errors and is of poor quality. 0-­‐Student did not attempt extension; extension was not included in lab report. 74
Exploring the Stars Today you are going to be traveling the solar system! In fact you will be visiting different planets! Each lab station is now a planet. You will find that there are objects on the table and your job is to mass each object and report its weight in the data table below. In 2
a previous lab, you discovered that the acceleration on Earth due to gravity was 9.8 m/s . Knowing this information, you must find the “weight” of each object on each of the different planets. It is also important to find relationships between weight, gravity and mass. Be sure to check your triple beam balance and start the pointer on zero. The balance must be calibrated to give you the correct value. Use units on all calculations. Show your work and show units. Then answer the discovery questions when you are done. You will need to convert (g) to (kg)-­‐ You may use a calculator if needed. Gravity Lab/Worksheet Station 1 Description of Planet (2 things learned) Planet Object Earth 1 Earth 2 Mass from TBB (g) Mass (kg) Planet’s Gravity 2
(m/s ) Planet’s Mass (kg) Planet’s Density 3
(kg/cm ) Planet’s Diameter (km) Station 2 Jupiter 3 Jupiter 4 Station 3 Mercury 5 Mercury 6 Station 4 Moon 7 Moon 8 Station 5 Neptune 9 Neptune 10 Station 6 Mars 11 Mars 12 75
Station 7 Saturn Saturn 13 14 Station 8 Sun Sun 15 16 Station 9 Venus Venus 17 18 Station 10 Uranus 19 20 To find weight: Mass (kg) x Acceleration due to gravity m/s2 = Weight kg(m/s2) or (N) Uranus Step 2-­‐ Now that you have visited all of the planets in your solar system sit down with your fellow explorers and find the weight of each object based on its acceleration due to gravity. OBJECT 1 2 3 4 5 6 7 8 9 10 ACCELERATIO N DUE TO GRAVITY 2
(m/s ) MASS (KG) FORCE EXERTED MASS OBJECT ON PLANET (KG) (N) WEIGHT OF OBJECT 2 (kg x m/s ) 11 12 13 14 15 16 17 18 19 20 ACCELERATIO N DUE TO GRAVITY 2
(m/s ) FORCE EXERTED ON PLANET (N) WEIGHT OF OBJECT 2 (kg x m/s ) 76
Gravity Lab Follow-­‐Up Questions 1. A student says to his/her teacher, “I am going to find the weight of this object by using the triple beam balance.” Explain how this comment could be incorrect. Is mass and weight the same concept? Explain by using the proper vocabulary, underline the vocabulary, and use complete sentences. 2. If you were to take a backpack from Earth to Mars would its mass change or stay the same? Explain. 3. Analyze: Based on what you have seen, how does the mass of a planet impact the gravity it has? Explain the relationship between mass and gravity. Use complete sentences. 4. Analyze: Which of the planets has a greater gravity than Earth? Do these planets also have greater mass? 5. How are weight and force related? Explain using complete sentences. 6. Draw a FORCE DIAGRAM showing one of the objects from the lab. Be sure to : picture of object, name of object ground of planet, name of planet _size of force and direction of force 7. PREDICT: How much force would an object of 50g have on Earth? Draw and label a force diagram. 77
8. PREDICT: How much force would an object of 150 g have on a planet that had 3x the gravity of earth? Explain your answer in complete sentences. 9. PREDICT: How much force would an object of 20 g have on a planet that was ½ the size of Earth? Explain your answer in complete sentences. 10. PREDICT: How do you think increasing a planet’s size would impact its ability to pull objects towards 11. What did you learn about the relationship between weight, force, gravity, mass and acceleration? Explain what you “learned” from this lab. Vocabulary: Mass Weight Acceleration Force 78
LAB AND READING ASSIGNMENT/NOTE TAKING GUIDE Investigate Momentum-­‐ What happens when objects collide? 7. How is momentum different than inertia? Read pages 64-­‐69 in your book. Answer the following questions. 1. Any moving object has what kind of property? 2. What is momentum defined as? 3. Which object will have more momentum, a tennis ball or a wrecking ball? Explain your answer 9. If you had two wrecking balls, one moving faster than the other, which would be able to do the MOST damage? How do you know? 4. How is momentum similar to inertia? Explain. 10. In the formula for momentum, “p ” stands for…? 11. What are the units for momentum? Why are these the units for momentum? 5. What is the formula for momentum? 12. Is momentum a vector? What is a vector? 6. What two things must you know to find the momentum of an object? SHOW THE FORMULA, WORK, ANSWER AND UNITS 13. What is the momentum of a 1.5 kg ball moving at 2 m/s? FORMULA 8. Which object will have MORE momentum, a fast moving wrecking ball or a slow moving wrecking ball? Explain. WORK ANSWER UNITS 79
14. What is the momentum of a 2.5 g ball moving at 5 m/s? FORMULA WORK ANSWER UNITS 15. Define: Collision 16. What is one way in which objects transfer momentum? Explain. 18. When you have a collision between two objects what two things CHANGE? 23. What measurements are needed to calculate force? 24. Is there any difference between force and momentum? Explain your answer. 19. Define: Conservation of Momentum. 25. In collisions, forces are and . 26. Is momentum conserved in collisions? Explain. 20. How much an object’s momentum changes when a force is applied depends on what two things? Explain. 27. Momentum is a property of a object. 21. To find the total momentum of objects moving in the same direction, what should you do with the momenta of the objects? 17. What is a “ sy stem ” as defined and explain in your book on page 67? 22. For two objects that are traveling in opposite directions, what should you do to find the momenta of the objects? 28. Are collisions the ONLY events in which momentum is conserved? Explain. 80 29. What is the momentum of a 100 k g ball moving at 15 m/s? FORMULA WORK ANSWER UNITS 30. What is the momentum of a 12.5 g ball moving at 15 m/s? FORMULA WORK ANSWER UNITS CLASS DISCUSSION/ NOTES-­‐ WRITE THE NOTES FROM THE SMART BOARD DOWN. Found in •
Symbol for momentum is Symbol for m ass is •
Units for momentum is _. More mass= more •
Momentum takes into account •
Collision -­‐Two objects in close contact exchange and The total momentum of a system of objects change, as long as no outside forces are acting on that system. •
To find total momentum of objects moving in the SAME direction, •
Objects traveling in opposite directions, objects. Is a measure of in motion. Formula is: •
_. Symbol for velocity is Momentum Is a _. Momentum depends on _. it has size and direction) _the momenta of the objects. _the momentum from one another 81 Using your text book (p. 77-­‐ 83 and page 122 – 124) 1. Define: Kinetic Energy 2. Define: Potential Energy 3. Moving objects have what type of energy? 4. The faster an object moves, the more energy it has. 5. How are kinetic energy and potential energy DIFFERENT? Explain. 6. Draw a picture of a roller coaster and explain which locations the roller coaster would have the greatest potential energy and the greatest kinetic energy. 7. Define: Gravity 8. Do all planets have the same gravity? Explain. 9. Gravity is called the _force because it acts on any two masses anywhere in the universe. 10. On earth, the gravity is _. 11. In the spring scale lab you calculated acceleration due to gravity as 12. The more mass two objects have, the more _. of gravity the masses will exert on each other. 13. What is the relationship between the mass of an object and the force of gravity? 82 14. Knowing that planets are different in masses/size, explain the difference of the force of gravity on an object (like an astronaut) if he/she is near a large/massive planet vs. a small, less massive planet. Explain. . 15. As the distance between the objects increases, the force of gravity 16. In a vacuum, where there is no air, all falling objects have the acceleration due to gravity. 17. If you were to go to another planet, would your weight be the same? Explain. 18. Compare the term “ w eig ht” t o t he term “mass ”. How are they DIFFERENT? 19. Define: Mass 20. Define: Weight 21. An object’s weight is dependent on the force of acting on it. 22. When you are using a triple beam balance, are you measuring weight or mass? Explain. Gravity and Weight Problems units for weight_ Formula to find the weight of an object Show work Planet A Gravity 15.6 m/s2, astronaut 85.6 kg = weight_ Planet B Gravity 6.2 m/s2, astronaut 60.2 kg= weight Planet C Gravity 21.6 m/s2, astronaut 26.9 kg = weight Why are the units for weight the same as the units for force? 83 Chap 2 Power Point Notes and Discussion: Gravity is the of attraction between two of the objects. The force of gravity depends on the Friction is the force that _. motion between two that are pressed together. Draw a picture of an object moving to the right and show how friction “opposes” its motion. Potential Vs. Kinetic Energy 1. Define: Potential Energy 2. Define: Kinetic Energy 3. Draw a picture of a roller coaster and explain where the roller coaster has the most kinetic energy and the most potential energy. 84 Motion and Forces TEST Study Guide L1) Know the following terms/definitions/equations. Position Location Relative location Motion Relative Motion Speed Velocity Acceleration Vector Force Net Force Balanced/Unbalanced Forces Newton’s 1st Law of Motion Newton’s 2nd Law of Motion Newton’s 3rd Law of Motion Inertia L2) You should be able to solve the following problems (and answer with CORRECT UNITS). Velocity: A man was running across a bridge for 5 minutes. He started at the 2000m mark on the bridge, and ended at the 1000m mark on the bridge. What was his velocity? Pedro O’Shea is a famous soccer player. He plays for Team Brevetti F.C. in Edmond. The other day, he was clocked running 100m across the soccer field in 5 seconds. What was his velocity? Acceleration: A car is driving 20m/s down the county road and sees a stop sign up ahead. He slows down his car until he is at a complete stop 10 seconds later. What was his acceleration? After looking both ways, the driver of the car begins driving again, and in 6 seconds he is driving 25m/s. What was his acceleration? Force: 2
What is the Force needed to accelerate a .02kg mass 50m/s ? What is the acceleration of a 50kg object that has been given a 20N push? What is the mass of a car that was accelerated 25m/s2 by a force of 150N? You should be able to find the NET Force of force diagrams, tell if there will be motion, and in what direction the motion will be. 85