TABLE OF CONTENTS
EXPERIMENT
PAGE
THE CHASE
1
SHOOT FOR YOUR GRADE
4
FRICTION LAB
7
COLLISIONS
9
SPRINGS AND PENDULUMS
10
PENDULUMS AND YOU
13
DEMO: CHANGE OF PHASE
15
SPECIFIC HEAT
18
VIRTUAL LAB: FIRST LAW OF THERMODYNAMICS
22
THE SPEED OF SOUND
26
SPEED OF SOUND IN AIR (RESONANCE TUBE)
27
LENS AND MIRROR
29
CIRCUITS
31
i
KINEMATICS
OF MOTION
EXPERIMENT: THE CHASE
A car moving along the highway posses a parked police car with a radar detector. Just as the car
passes, the police car starts to pursue, moving with a constant acceleration. The police car catches
up with the car just as it leaves the jurisdiction of the police officer.
Hypothesis:
Sketch the position-time graphs and the velocity-time graphs for this chase, then simulate the
chase.
Materials: battery powered car, marble, masking tape, stopwatch, v-channel aluminum track, ring
stand, clamp
Procedure:
1. Identify the variables in this activity.
2. Determine how you will give the ball a constant acceleration.
3. Devise a method to ensure that both objects reach the end of the track at the same time.
1
4. Construct a data table that will show the positions of both objects at the beginning, the
halfway point, and the end of the chase.
5. Perform the simulation.
6. Construct x/t (position vs. time) and v/t (velocity vs. time) graphs from your data.
Compare these to your original graphs.
7. Return materials to their original places.
Questions:
1. Compare the velocities of the cars at the beginning and the end of the chase.
2
2. At any time during the chase did the cars ever have the same velocity? If so, mark these
points on the graph.
3. Find the average velocity of the police car.
4. Find the average velocity of the car.
5. Compare the average velocity of the police car to that of the car.
6. Explain why it took the police car so long to catch the car after it sped by.
7. If the speeder accelerated at the exact same rate of the police car at the moment the
speeder passes the police car, would the police car ever catch the speeder? Why or why
not?
3
PROJECTILE
MOTION
EXPERIMENT: SHOOT FOR YOUR GRADE
Objective: Predict the landing spot of a projectile launched horizontally from an elevated platform.
Materials: incline, marble, stopwatch, meter stick
Methods
1. Roll the marble down the ramp several times, recording the necessary data to determine the
speed of the ball at the bottom of the ramp. Show your data below. IMPORTANT: The marble
must never leave the table when taking data. Only when you are ready to shoot for your grade will the marble
be allowed to land on the floor. If the marble leaves the floor, you get one warning, then a zero.
2. Take any measurements needed to calculate the time for free fall for the projectile.
3. Using the velocity and time data, predict by calculation the landing spot of your projectile.
Measure this calculated distance along the floor from a spot on the floor directly below the edge of
the table. Place the target sheet at this position, carefully lining up the paper with the projected
path of the marble.
4. Call over the physics teacher before firing the projectile for your grade. The target sheet gives
you your grade. You have only one chance at your grade.
4
Questions:
1. A cliff diver leaps off a high cliff into the water below. The diver leaves the cliff with a
horizontal speed of 8 m/s. Determine the horizontal and vertical velocities of the diver
after 1 second, 2 seconds, and 3 seconds.
Horiz. Velocity (m/s)
Vert. Velocity (m/s)
After 1 second
After 2 seconds
After 3 seconds
2. A blue ball rolling at a high speed across the horizontal surface of an elevated table leaves
the table at the same time that a red ball drops off the same table from rest. Which ball
(blue, red or neither) will hit the ground first. Justify your answer with good reasoning
and the language of physics.
3. An airplane, flying at a high altitude, drops a flare from below its cargo area. After releasing
the flare, the plane continues in its straight-line constant speed motion as the flare falls
towards the ground. Assuming that there is a negligible amount of air resistance, five
seconds later the flare will be positioned ...
a. directly below the position of the cargo area.
b. slightly behind the position of the cargo area.
c. slightly ahead the position of the cargo area.
Justify your answer with good reasoning and the language of physics.
5
BULLS
EYE!
6
FORCE AND
FRICTION
EXPERIMENT: FRICTION
Objective: Observe and distinguish between static and kinetic friction. Determine if surface area
and type of material changes the coefficient of friction.
Materials: Friction block, 10N spring scale, mass set, wooden track.
Safety: Wear close-toed shoes
Procedure: There are eight part to this experiment so read all the procedures before beginning.
Take the block and place the wide side down on the lab counter. Place a 500g mass on top of the
block. Next, attach the spring scale to the block (make sure you zero the spring scale). Holding
the spring scale parallel with the counter pull on the block until it starts to move. Record the
maximum force read from the spring scale in the data table. After the block begins to move try to
maintain a constant velocity with the block and read the force from the spring scale. Record this
value in the data table then add 500g and repeat the experiment. Finally add another 500g and
repeat.
Repeat the experiment with the block on the narrow side (be careful, it is slightly unstable). After
that place the block on the wooden track and repeat all steps
Data:
Weight of block (Newton’s)
Trial
Wide (counter)
Narrow
Wide 2 (ramp)
Static Force (500g)
Kinetic Force
Static (1000g)
Kinetic
Static (1500g)
Kinetic
Calculations:
1. Calculate the total weight of the block
Trial
Block + 500g
Block + 1000g
Block + 1500g
Weight (N)
7
Narrow 2
2. Draw a free body diagram for the 500g experiment (static and kinetic cases).
3. Calculate the coefficients of static and kinetic friction using the force recorded in each
case.
Trial
Wide (counter)
Narrow
Wide 2 (ramp)
Narrow 2
s (500g)
k
s (1000g)
k
s (1500g)
k
Questions:
1. Does the surface area change the coefficient of friction?
2. Does the normal force change the coefficient of friction?
3. Write a 5 sentence conclusion about this lab (I thought it was fun is not a conclusion, it is
an opinion).
8
MOMENTUM
EXPERIMENT: COLLISIONS
Purpose: To observe different types of collisions and their characteristics.
Materials: Two dynamics carts, two pieces of duct tape
Procedure:
Part A
1. Push the two dynamics carts towards each other with a moderate force to produce a
collision. Push the carts so that the stopper on one of the carts collides with the smooth
end of the other cart.
2. Describe what happens to each cart. Use terms such as pushed cart, and stationary cart
and describe their relative velocities before and after the collision.
3. Which type of collision did you produce?
Part B
1. Put a small amount of rolled duct tape on the smooth ends of each cart . This is where
they are going to be colliding.
2. Push one of the carts with a moderate force, while leaving the other cart at rest.
3. Describe what happens to each cart. Use terms such as pushed cart, and stationary cart
and describe their relative velocities before and after the collision.
4. Which type of collision did you produce?
9
SIMPLE
HARMONIC
MOTION
EXPERIMENT: SPRINGS AND PENDULUMS
Purpose: To investigate the approximate equations for spring oscillators and simple pendulums.
We will verify the accuracy of the equations in the “real world.” A percent difference of less than
8% is considered very good.
Materials:
 Spring
 Ring stand and test tube clamp
 Meter stick
 Stopwatch
 1 meter of string
 Mass set
Methods:
Spring oscillator (sprilator)
First let’s set up the spring oscillator. Set up your ring stand like figure 1. To find your spring
constant, measure the length of the spring with no weight on it. Add the 0.5kg mass and measure
the new length of the spring. Use the chart to find the spring constant.
To measure the period of the oscillator, use three different masses, at least 150g but no more than
500g. Start that spring moving and while timing it, let it go through 10 cycles. Record this in the
chart. Repeat this for two other masses and record your data.
Pendulum
Make your pendulum as shown in figure 2. We are going the test two things, the mass and the
length. For the mass test you should not change the length of the string! Measure the length of
the pendulum as shown. Using three different masses measure the time for ten oscillations and
record them in the chart. Try to use the same angle of displacement each time as to only change
one variable at a time.
Using the same mass for the next three trials is very important! Now measure the time for 10
oscillations and record it. Change the length of the pendulum and repeat.
L
Figure 1
Figure 2
10
Measurements: Spring Oscillator
Length
Mass
Mass 1
Mass 2
Mass 3
Length Stretched
Weight (m*9.81)
Period
Period
Period
Spring constant calculated using Hooke’s Law: _________
Pendulum (same length):
Length
Mass 1
Mass 2
Mass 3
Period
Period
Period
Length 1
Length 2
Length 3
Period
Period
Period
Pendulum (same mass):
Mass
Calculations:
Using your equations calculate what the period should be for the two oscillators
Spring:
Spring Constant
Mass 1
Mass 2
Mass 3
Period
Period
Period
Length 1
Length 2
Length 3
Period
Period
Period
Pendulum:
Mass
11
Questions:
1. Are your measured values the same as your calculated values?
2. To what do you attribute the differences if any?
3. Find the percent error in your measurements.
measured period  calculated period
% error 
 100
calculated period
Resources:
http://www.her.itesm.mx/academia/profesional/cursos/fisica_2000/FisicaII/PHYSENGL/sp
ringpendulum.htm
http://www.netzmedien.de/software/download/java/oszillator/
http://cat.sckans.edu/physics/shm.htm
4. Do you think the angle of the swing or the displacement of the spring affects the period?
(Please use a scientific approach to answer this).
5. Write a 4-5 sentence conclusion about your results.
12
CONSERVATION OF
ENERGY
EXPERIMENT: PENDULUMS AND YOU
Objective: In this lab we are investigating conservation of energy using a pendulum. We know
energy is conserved, but some of the mechanical energy is turned into non-mechanical energy by
heating the surface of the objects. We can assume the pendulum loses only a small amount of
energy during its swing but the block loses all mechanical energy because of friction. What we
want to find is the percentage of energy lost by the pendulum and the frictional force.
Materials:
Quantity
1
2
1
1
1
1
Description
String 0.5 meters
0.5 kg mass
Block
Ring stand
Test tube clamp
meter stick
Methods: Set up your apparatus to look like Figure 1.
1. Measure the mass of your
block on the balance and
record it.
2. Place the block so it touches
the pendulum when the
pendulum is in equilibrium.
Figure 1
3. Measure the height of the
pendulum from the table
when it is at equilibrium and
record it.
4. Pull the pendulum back and
measure its height from the
table and record it. Subtract step 3 from step 4 and record this in your data table for the
height of the pendulum.
5. Release the pendulum so that it hits the block then measure and record how far the block
slides after the pendulum strikes it.
Now add 0.5 kg to the block and repeat steps 2 thru 5 raising the pendulum to the same height.
Data & Results:
Mass of pendulum _______ kg
Height of pendulum from step 3 _______ (m)
Height of pendulum from step 4 _______ (m)
Step 4 – Step 3 = ________ Total change in height (Record in data table)
13
Trial
Mass of block (kg)
Data table
Height of pendulum (m)
Distance block slides (m)
Mass of block + 0.5kg
Height of pendulum (m)
Distance block slides (m)
1
2
3
Trial
1
2
3
Calculations (show all work):
1. Calculate the initial amount of potential energy in the pendulum.
2. Calculate the velocity of the pendulum when it strikes the block.
3. Calculate the normal force on your block (mass x 9.81 m/s2), and the force of friction if
= .242 (Ff = Fn).
4. How much work is done by friction (remember work equals force x distance)?
5. Calculate the amount of energy lost. Note: “[#]” indicates where to find the value.
Percent energy loss 
PE[1]  W f [4]
PE[1]
100
Questions:
1. What was your amount of energy loss, and where did the energy go?
2. Does the pendulum lose energy, if so how could we measure the amount lost?
14
THERMODYNAMICS
EXPERIMENT /DEMO: CHANGE OF PHASE
Objectives: Perform calculations with specific heat capacity, perform calculations involving latent
heat, interpret the various sections of a heating curve.
Materials: Beaker, hot plate, ice, CBL unit with temperature probe
Procedures:
1. Your teacher will set up the CBL unit with the hot plate, beaker and ice.
Mass of ice in beaker = _______________
2. Data will be collected for 30 minutes.
3. Copy the data from the CBL unit onto the graph below. Important points are where the
graph of the heating curve changes.
temperature (F)














15


time (minutes)


4. Calculate the amount of heat required for the ice to reach 0 ºC.
5. Calculate the amount of heat required to melt the ice.
(The ice remains at 0 ºC during this process).
6. Calculate the amount of heat required to heat the water from 0 ºC to 100 ºC.
7. Calculate the amount of heat required to vaporize the water.
(The water remains at 100 ºC during this process).
8. Calculate the amount of heat it would required to heat the steam from 100 ºC to 125 ºC.
9. What was the total amount of heat required to heat the ice at the initial temperature to
steam at 125 ºC?
Questions:
1. Why does steam at 100 ºC cause more severe burns than does liquid water at 100 ºC?
16
2. Why does the temperature of a substance not change when the substance is changing
phases?
3. The idealized graph of the temperature change of water is shown below. What do the
segments B and D indicate?
4. Did energy transfer happen continually throughout the process pictured above? Explain.
5. Did the temperature increase at the same rate throughout the process? Explain.
17
THERMODYNAMICS
EXPERIMENT: SPECIFIC HEAT
Objectives: Measure heat exchange using a calorimeter, Calculate the specific heat of metals,
Hypothesize about the sources of experimental error, identify a material based on its specific heat.
Materials: 400 mL beaker, hot plate, string, specific heat metal set, balance, water, polystyrene cup
or calorimeter, thermometer
Safety: Safety Goggles
Introduction:
One property of a substance is the amount of energy that it can absorb per unit mass. This
property is called specific heat, Cs. The specific heat is the amount of energy , measured in Joules,
needed to raise the temperature of 1 kg of a material 1° C (1 K).
A calorimeter is a device that measures the specific heat of a substance. The polystyrene cup, used
as a calorimeter, insulates the water-metal system from the environment, while absorbing a
negligible amount of heat. Since energy always flows from a hotter object to a cooler one and the
total energy of a closed, isolated system always remains constant, the heat energy, Q, lost by one
part of the system, is gained by the other:
Qlost by the metal = Qgained by the water
In this lab, you will determine the specific heat of two different metals. You heat a metal to a
known temperature and put it in the calorimeter containing a known mass of water at a measured
temperature. You measure the final temperature of the water and material in the calorimeter.
Given the specific heat of water (4180 J/kg•K) and the temperature change of the water, you can
calculate the heat gained by the water (heat lost by the metal):
Qgained by the water = mwater ∆Twater(4180 J/kg•K)
Since the heat lost by the metal is: Qlost by the metal = mmetal ∆TmetalCmetal
The specific heat of the metal can be calculated as follows: Cmetal =
Qgained by thewater
mmetal Tmetal
Procedure:
1. Safety goggles must be worn for this lab. CAUTION: Be careful when handling hot
glassware, metals, or hot water.
2. Fill a 400 mL beaker about 350 ml of water. Place the beaker of water on a hot plate and
begin heating it.
3. While waiting for the water to boil, measure and record in Table 1 the mass of the metal(s)
you are using and the mass of the inner calorimeter cup.
4. Using the aluminum stirring rod, lower one of the metal samples into the boiling water, as
shown in Figure A. Leave the metal in the boiling water for at least 5 minutes.
18
5. Fill the calorimeter cup half full of tap water.
6. Measure and record in Table 1 the total mass of the water and cup.
7. Using the thermometer, measure and record in Table 1 the temperature of the water in the
calorimeter cup.
Calculator instructions for measuring temperature:
a) Turn on your CBL2® and TI Calculator.
b) Press the [APPS] Button
c) Scroll down and find the “Datamate” app.
d) With the temperature probe plugged into “CH 1” on the CBL2®, select the app. by
pressing [ENTER]
e) When the app. starts in should recognize the probe and give a real-time read out in the
upper right corner of the screen.
8. Using the thermometer, measure and record in Table 1 the temperature of the boiling
water in the beaker, just before you will be removing the metal. Do not place the
thermometer on the hot plate.
9. Cool the thermometer then place it in the calorimeter cup.
10. Carefully remove the metal from the boiling water and quickly lower it into the water in
the calorimeter cup with the thermometer.
11. Gently stir the water in the calorimeter cup for several minutes with the stirring rod,
keeping the thermometer from touching the metal.
Calculator instructions for measuring temperature:
f) Press [2] the start the data collection
g) Watch the graph and when it begins to level out press [STO] to stop the data
collection.
h) Trace the graph to find the final, equilibrium temperature
12. After 5- 10 minutes, record the final temperature of the metal and water in Table 1.
Data and Observations:
TABLE 1
Trial 1
Type of metal
Mass of calorimeter cup (kg)
Mass of calorimeter cup and water (kg)
Mass of metal (kg)
Initial temperature of tap water (°C)
Temperature of hot metal (°C)
Final temperature of metal and tap water (°C)
19
Trial 2
TABLE 2
Trial 1
Trial 2
Mass of room-temperature water (kg)
∆T metal (°C)
∆T room-temperature water (°C)
Heat gained by the water
Calculated Specific Heat of metal
Relative Error
Analysis and Conclusions: (show all work)
1. For each trial, calculate the mass of the room-temperature water, the change in temperature
of the metal, and the change in temperature of the water in the polystyrene cup by using
the values from Table 1. Record these values in Table 2.
2. For each trial calculate the heat gained by the water (heat lost by the metal). Record these
values in Table 2.
3. For each trial, calculate the specific heat of the metal. For each metal sample us the value
for heat gained by the water that you calculated in Question 2. Record these values in
Table 2.
20
4. For each trial, use the values for specific heat of substances found on page xxiii to calculate
the relative error between your value for specific heat and the accepted value for the metal.
Record these values in Table 2.
| accepted  experiment al |
Relative Error 
x100
accepted
5. If you had discrepancies between your values for specific heat of the metal samples and the
accepted values, suggest sources of uncertainty (error) in your measurements that may have
contributed to the difference.
Application: (show all work)
1. A 100.0 g sample of a substance is heated to 100.0 °C and put in a calorimeter cup (having a
negligible amount of heat absorption) containing 150.0 g of water at 25 °C. The sample raises the
temperature of the water to 32.1 °C. Find the specific heat of the substance, then use the specific
heat values on page xxiii to identify the substance.
21
THERMODYNAMICS
VIRTUAL LAB: FIRST LAW OF THERMODYNAMICS
Open the browser and go to the website:
http://jersey.uoregon.edu/vlab/Thermodynamics/index.html
Experimental Instructions:
This applet is designed to simulate the diffusion process which occurs when gases of different
temperatures are mixed. To activate the mixing click one time on the red vertical bar that separates
the two chambers. After a few moments, the bar will turn green and the gases will start to mix and
share their energy. The counters in the respective chambers indicate the number of particles in
that chamber. The thermometers will start to change temperature as the mixing process is
occurring. Eventually both chambers will reach the same temperature.
In order for this simulation to properly run – it’s important that the user not be doing other
activities on the machine as this will interfere with the timing aspects of the experiment.
Different initial conditions are setup in a series of experiments and questions related to that
experiment can be found underneath the apparatus.
First experiment
1. Write down the initial temperatures for each of the two chambers.
1st chamber: __________
2nd chamber: ________
2. Click once on the vertical red bar (and WAIT!); observe the mixing of the gases
3. Time how long it takes for the temperature to equilibrate.
Questions:
1. What do you think the final equilibrium temperature will be?
2. Why are there more particles in the cold side than the warm side when you first start mixing
the chambers?
3. How long does it take for the temperature to equilibrate?
4. After equilibrium is reached, close the chamber door and raise the temperature in the right
chamber to 900 degrees. Reopen the chamber to determine what the new equilibrium temperature
is.
New equilibrium temp: __________
Second experiment
1. Write down the initial temperatures for each of the two chambers.
1st chamber: __________
2nd chamber: ________
2. Click once on the vertical red bar (and WAIT!); observe the mixing of the gases
3. Time how long it takes for the temperature to equilibrate.
22
Questions:
1. What do you think the final equilibrium temperature will be?
2. Will this system take a longer time or shorter time to equilibrate than the previous one?
Explain.
Third experiment
1. Write down the initial temperatures for each of the two chambers.
1st chamber: __________
2nd chamber: ________
2. Click once on the vertical red bar (and WAIT!); observe the mixing of the gases
3. Time how long it takes for the temperature to equilibrate.
Questions:
1. What do you think the final equilibrium temperature will be?
2. Will this system take a longer or shorter time to equilibrate than experiment 2, which had the
same temperature difference?
Fourth experiment
1. Write down the initial temperatures for each of the two chambers.
1st chamber: __________
2nd chamber: ________
2. Write down how many particles are in each gas initially.
1st chamber: __________
2nd chamber: ________
3. Click once on the vertical red bar (and WAIT!); observe the mixing of the gases
4. Time how long it takes for about 125 particles to exist in each chamber.
QUESTIONS:
1. What do you think the final equilibrium temperature will be?
2. Will this system reach equilibrium faster or slower than it took in the First experiment with the
same temperature difference? Explain.
3. Compare the rate of temperature change on the left and right sides? Why are they so different?
4. Time how long it takes for about 125 particles to exist in each chamber and note the
temperature difference the first time this occurs.
23
Fifth experiment
1. Write down the initial temperatures for each of the two chambers.
1st chamber: __________
2nd chamber: ________
2. Write down how many particles are in each gas initially.
1st chamber: __________
2nd chamber: ________
3. Click once on the vertical red bar (and WAIT!); observe the mixing of the gases
4. Time how long it takes for about 125 particles to exist in each chamber.
Questions:
1. What do you think the final equilibrium temperature will be?
2. Will this system reach equilibrium faster or slower than it took in the First experiment with the
same temperature difference? Explain.
3. Compare the rate of temperature change on the left and right sides? Why are they so different?
4. Time how long it takes for about 125 particles to exist in each chamber and note the
temperature difference the first time this occurs.
5. How is this experiment different from experiment four?
Sixth experiment
1. Write down the initial temperatures for each of the two chambers.
1st chamber: __________
2nd chamber: ________
2. Write down how many particles are in each gas initially.
1st chamber: __________
2nd chamber: ________
3. Click once on the vertical red bar (and WAIT!); observe the mixing of the gases
4. Time how long it takes for about 125 particles to exist in each chamber.
Questions:
1. What do you think the final equilibrium temperature will be?
2. What do you think will happen to the two particles in the left chamber?
24
3. How long will it take the left chamber to have a temperature that is within 10% of the right
chamber?
4. How is this experiment different from experiment four?
Seventh experiment
1. You should restart Netscape/Internet Explorer for this
2. Simple – it’s a game - subvert the laws of physics - try to get all the particles on one side or the
other and then close the chambers. Initially try to do this without adding energy to the system. If
this fails, do the following:
3. You may adjust the temperatures of the chambers by grabbing the thermometer with the
pointer and moving it. Can you figure out the scheme to get all the particles to one side. It is
possible ...
Explain what you did to get all particles in one chamber. Why did this work?
Summarizing
1. State the first law of thermodynamics.
2. State some observations from the experiments that utilized/applied to the first law of
thermodynamics.
3. How does the temperature equilibrium point relate to the starting temperatures in each
chamber?
4. Explain in terms of physics why a temperature in a chamber increases.
5. Does the number of the particles in a chamber affect temperature equilibrium?
25
WAVE
MOTION
EXPERIMENT: THE SPEED OF SOUND
Purpose: The speed of light is much faster than the speed of sound. During a thunderstorm you
can see the lightning before you hear the thunder. The lightning causes the thunder so they occur
at the same time, but the sound takes much longer to reach your ears than the light to reach your
eyes. French scientist, in 1738 fired a canon on a hill and timed the difference between the flash
and the bang from a know distance. We are going to recreate this experiment.
Materials: Hammer, stop watch, metal wheel
Method: Go outside to a large field and measure off 100 meters. Have one student hit the metal
with the hammer. The timers will begin when they see the hammer hit the metal and stop when
they hear the noise. Do several times at various positions and record your information.
Data:
100m
Trial
150m
Time (s)
1
2
3
Trial
Remember
d
v
t
Average
Time (s)
1
2
3
Average
Calculations:
1. Calculate the speed in each trial.
2. Calculate the percent error to find the theoretical speed use the following formula
% error 
theoretical  measured
theoretical
theoretica l speed of sound  331 1 
 
T oC
273
Questions:
1. What factors might have caused your error?
2. Explain how you could determine how far you a lightning strike using a stopwatch
3. In early days the train robbers would put their ear to the train tracks to determine if the
train they where robbing was near. Explain why they would do that instead of just
listening for it.
26
WAVE
MOTION
EXPERIMENT: SPEED OF SOUND IN AIR (RESONANCE TUBE)
Purpose: The speed of sound in air is measured using a variable length column of air.
Materials: Resonance-tube apparatus, tuning fork, rubber hammer, meter stick, rubber stopper,
clamp and stand
Methods: A. Position the reservoir adjacent to the 50 cm mark on the resonance tube. Now fill
the reservoir about 1/2 full and hold it above the mouth of the resonance tube. Caution: Hold the
tuning fork off to the side when you strike it and then bring it over the mouth of the tube. Also, do not
strike the tuning fork too hard because you will generate harmonics of the fork's fundamental
frequency which do cause unwanted resonances. Hold the fork with the exact alignment as
illustrated in the theory section for maximum sound intensity.
B. Raise the reservoir so that the level of the water is almost to the top of the tube. Using a rubber
mallet, strike the tuning fork and lower the water level slowly until a marked increase in sound
intensity is heard. Continue to refine your location until you have located the point of maximum
sound intensity. This is the first resonance point.
C. Lower the water level in the tube and locate the second resonance point as you did the first.
Locate additional resonance points if they exist. Record the room temperature on the wall
thermometer, as you will need it subsequently.
D. Repeat the above for a tuning fork with a different frequency.
Calculations: Determine the wavelength (l) of the sound from the standing wave resonance
conditions as illustrated in the theory section. Use only the difference in water levels for successive
resonance conditions. Do not use the first resonance condition () by itself to determine l because
the tuning fork is an undetermined distance above the mouth of the tube. Find the wavelength for
each tuning fork by the above method. Using the formula V=fl, compute the sound velocity for
each tuning fork. The accepted value for the velocity of sound in air is 331 m/sec at 0oC and
increases about 0.6 m/sec for each degree above 0oC.
Questions:
1.
2.
3.
4.
Is the surface of the water a true node? Explain.
What is the major cause for error?
Why is it necessary to avoid striking the tuning fork too hard?
Explain why sound travels faster in warm air than in cool air. Suppose the room
temperature (in degrees Celsius) were 10% higher, how would your resonance lengths
change?
5. If the distance from a point sound source is tripled, by what factor does the sound intensity
(or loudness) decrease?
6. In this experiment we used tubes that were opened at one end and closed at the other end.
The closed end is the water's surface. The first resonance condition occurs at l/4. Could
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this experiment be done with tubes open at both ends? Explain. What is the first resonance
condition for tubes with both ends open?
7. An airplane mechanic (standing still) notices that the sound from a twin-engine aircraft
rapidly varies in loudness when both engines are running. What could be causing this
variation back and forth between loud and soft?
Theory: Standing wave resonance conditions for sound waves in a variable length column of air.
The sound will have maximum intensity at these conditions.
L = difference in water levels for successive resonance conditions
V = fL
where
f = frequency of tuning fork in Hz
l = wavelength of sound in meters
V = velocity of sound in m/sec
Vsound in air = 331 + 0.6(ToC)
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WAVES AND
LIGHT
EXPERIMENT: LENS AND MIRROR
Purpose: To use conceptual knowledge from class to find the focal length of a lens and predict
where an image will be formed and to investigate concave and convex mirrors.
Materials:
 1 Concave lens/mirror
 1 Convex lens/mirror


1 Meter stick optics bench and parts
1 Light source
Method: The first objective is to find the focal length of the mirror. To do this, set the light
source at the 95 cm mark on your meter stick. Place the screen on the other end at 10 cm. Place
the convex lens at the 30 cm mark. Move the screen until the light bulb is in focus and record
your measurement. You will need to record the height of your image to calculate the
magnification, so using the ruler printed on the screen measure and record it. Now move the lens
to the 60 cm mark and repeat. Using your lens equation calculate the focal length for each case.
Now pick a place on the meter stick to put the lens at and calculate where the screen should be
placed. Put the screen there and record your observation. Next, set up this experiment with the
concave lens and record your observations. Next use the mirrors to look at the light bulb from
very close and then far away, record your observations.
Results/Data:
TABLE 1
Trial
do (cm)
Convex lens
65
Convex lens
35
di (cm)
ho (cm)
hi (cm)
Concave Lens
Close
Far
Convex Mirror
Concave
Mirror
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Analysis (show your work):
1. Calculate the focal length of the convex lens.
2. What were your observations from the prediction?
3. Calculate the magnification of the convex lens.
4. Describe your observations of the concave mirror.
5. When is the image magnification greater than 1 with the concave mirror? Describe when.
Questions:
1. Was the light bulb focused on the screen when you predicted where it should be?
2. What type of image was formed with the concave lens/ convex mirror?
3. If the screen in a movie theatre is 15m from the projector the film is 10cm from the lens
what is the focal length of the lens?
Conclusion:
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CIRCUITS
Experiment: Circuits Lab
A
Purpose: The following lab is designed to help investigate voltage and current in difference
circuits. You will set up your circuit by looking at the schematics and take the appropriate
measurements.
Materials: 7 wires w/ circuit board, voltmeter, three resistors (light bulb), power supply (cells or
battery), ammeter, knife switch (optional)
Safety: Use caution when handling resistors – they will get hot. Do not exceed the recommended
voltage.
Method: Using your materials build the circuit shown in Figure 1. This is a simple circuit. Do not
complete the circuit until instructed to do so. When your circuit matches Figure 1, ask the teacher
for approval before proceeding.
A
A
Figure 1
A
Figure 2
A
Figure 3
Figure 4
(Note: To measure the voltage, connect the voltmeter to the posts of the light bulb. This puts it
in parallel with the circuit. Connect the (-) post of the voltmeter to the side of the light bulb
closest to the (-) terminal of the battery. For the ammeter, connect the positive (+) side to the
positive (+) terminal of the battery and negative side to the negative termal in series)
Data/Results:
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Measure the following
1. The current in each branch of the circuit.
2. The potential difference across each light bulb.
3. Observe the intensity of the bulb.
Figure 1
Voltage across bulb
Figure 3
Voltage across bulb
Current
Figure 2
Voltage across bulb
Current
Current
Figure 4
Voltage across bulb
Current
Analysis:
Find the resistance in each light bulb using Ohm’s law
Questions:
1. Do you get the same resistance when the circuit is in series as when it is in parallel?
2. How does the current compare in each circuit?
3. How does the voltage compare in each circuit?
4. Compare the brightness of the bulbs in each circuit.
Conclusion: Write a 4 to 5 sentence conclusion about what you learned from this experiment
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