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

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.
  1. Determine how you will give the ball a constant acceleration.
  1. Devise a method to ensure that both objects reach the end of the track at the same time.
  1. Construct a data table that will show the positions of both objects at the beginning, the halfway point, and the end of the chase.
  1. Perform the simulation.
  1. Construct x/t (position vs. time) and v/t (velocity vs. time) graphs from your data. Compare these to your original graphs.
  1. Return materials to their original places.

Questions:

  1. Compare the velocities of the cars at the beginning and the end of the chase.
  1. At any time during the chase did the cars ever have the same velocity? If so, mark these points on the graph.
  2. Find the average velocity of the police car.
  1. Find the average velocity of the car.
  1. Compare the average velocity of the police car to that of the car.
  1. Explain why it took the police car so long to catch the car after it sped by.
  1. 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?

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.

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
  1. 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.
  1. 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 ...
  2. directly below the position of the cargo area.
  3. slightly behind the position of the cargo area.
  4. slightly ahead the position of the cargo area.

Justify your answer with good reasoning and the language of physics.

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) / Narrow 2
Static Force (500g)
Kinetic Force
Static (1000g)
Kinetic
Static (1500g)
Kinetic

Calculations:

  1. Calculate the total weight of the block

Trial / Weight (N)
Block + 500g
Block + 1000g
Block + 1500g
  1. Draw a free body diagram for the 500g experiment (static and kinetic cases).
  1. 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?
  1. Does the normal force change the coefficient of friction?
  1. Write a 5 sentence conclusion about this lab (I thought it was fun is not a conclusion, it is an opinion).

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.
  1. 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.
  1. Which type of collision did you produce?

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.

Figure 1Figure 2

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

Pendulum (same mass):

Mass / Length 1 / Length 2 / Length 3
Period / Period / Period

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

Pendulum:

Mass / Length 1 / Length 2 / Length 3
Period / Period / Period

Questions:

  1. Are your measured values the same as your calculated values?
  1. To what do you attribute the differences if any?
  1. Find the percent error in your measurements.

Resources:

  1. 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).
  1. Write a 4-5 sentence conclusion about your results.

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 / Description
1 / String 0.5 meters
2 / 0.5 kg mass
1 / Block
1 / Ring stand
1 / Test tube clamp
1 / 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.
  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)

Data table

Trial / Mass of block (kg) / Height of pendulum (m) / Distance block slides (m)
1
2
3
Trial / Mass of block + 0.5kg / Height of pendulum (m) / Distance block slides (m)
1
2
3

Calculations (show all work):

  1. Calculate the initial amount of potential energy in the pendulum.
  1. Calculate the velocity of the pendulum when it strikes the block.
  1. Calculate the normal force on your block (mass x 9.81 m/s2), and the force of friction if = .242 (Ff = Fn).
  1. How much work is done by friction (remember work equals force x distance)?
  1. Calculate the amount of energy lost. Note: “[#]” indicates where to find the value.

Questions:

  1. What was your amount of energy loss, and where did the energy go?
  1. Does the pendulum lose energy, if so how could we measure the amount lost?

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 = ______

  1. Data will be collected for 30 minutes.
  2. Copy the data from the CBL unit onto the graph below. Important points are where the graph of the heating curve changes.

  1. Calculate the amount of heat required for the ice to reach 0 ºC.
  1. Calculate the amount of heat required to melt the ice.

(The ice remains at 0 ºC during this process).

  1. Calculate the amount of heat required to heat the water from 0 ºC to 100 ºC.
  1. Calculate the amount of heat required to vaporize the water.

(The water remains at 100 ºC during this process).

  1. Calculate the amount of heat it would required to heat the steam from 100 ºC to 125 ºC.
  1. What was the total amount of heat required to heat the ice at theinitial 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?
  1. Why does the temperature of a substance not change when the substance is changing phases?
  1. The idealized graph of the temperature change of water is shown below. What do the segments B and D indicate?
  1. Did energy transfer happen continually throughout the process pictured above? Explain.
  1. Did the temperature increase at the same rate throughout the process? Explain.

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 =

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 theboiling water, as shown in Figure A. Leave the metal in the boiling water for at least 5 minutes.
  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 thecalorimeter cup.

Calculator instructions for measuring temperature: