7.3 2D Collisions Lab (1)

AP Physics 1A | 7.3 2D Collision Lab Lab Objectives: Determine if momentum is conserved for collisions that happen in more than one dimension. Procedure: 1. Go to https://phet.colorado.edu/sims/html/collision-lab/latest/collision-lab_en.html . 2. At the top of the screen, click the “Advanced” tab. 3. Locate the three buttons next to the data table and click the button “More data”. 4. On the right side of the screen uncheck the “reflecting border” box. 5. Record the mass, initial velocities, and initial momentum for each ball in the data table. 6. Click play and allow the two balls to collide. 7. After the collision, pause the simulation. Record the final velocities and momentum for each ball in the data table. 8. Click the Restart button. 9. Change the mass of ball 2 so that it is the same as ball 1. Repeat steps 5-8. 10. Change the mass of ball 2 to 1.500 kg and move the elasticity slider to 0%. Repeat steps 5-8. 11. Change the mass of ball 2 to 0.500 kg and keep the elasticity slider at 0%. Repeat steps 5-8. Note: If you cannot run flash on your device, you can watch the following video. It will give you the data that you need to complete this lab. https://youtu.be/KAIqbvoP9ik Data: (1 point per trial = 4 points) Before Collision Trial 1 Mass Ball 1 _______ kg Mass Ball 2 _________ kg Component Velocities v x (m/s) v y (m/s) v x (m/s) v y (m/s) Component Momenta p x (kgm/s) p y (kgm/s) p x (kgm/s) p y (kgm/s) Total Momentum in each direction Total p x momentum Calculation: Total p y momentum Calculation: Overall momentum Magnitude of momentum Calculation: Direction (degrees) Calculation: © Copyright 2017 Michigan Virtual Revised 5/18/2020 Page 1

After Collision Trial 1 Mass Ball 1 _______ kg Mass Ball 2 _________ kg Component Velocities v x (m/s) v y (m/s) v x (m/s) v y (m/s) Component Momenta p x (kgm/s) p y (kgm/s) p x (kgm/s) p y (kgm/s) Total Momentum in each direction Total p x momentum Calculation: Total p y momentum Calculation: Overall momentum Magnitude of momentum Calculation: Direction (degrees) Calculation: Before Collision Trial 2 Mass Ball 1 _______ kg Mass Ball 2 _________ kg Component Velocities v x (m/s) v y (m/s) v x (m/s) v y (m/s) Component Momenta p x (kgm/s) p y (kgm/s) p x (kgm/s) p y (kgm/s) Total Momentum in each direction Total p x momentum Calculation: Total p y momentum Calculation: Overall momentum Magnitude of momentum Calculation: Direction (degrees) Calculation: After Collision © Copyright 2017 Michigan Virtual Revised 5/18/2020 Page 2

Component Velocities v x (m/s) v y (m/s) v x (m/s) v y (m/s) Component Momenta p x (kgm/s) p y (kgm/s) p x (kgm/s) p y (kgm/s) Total Momentum in each direction Total p x momentum Calculation: Total p y momentum Calculation: Overall momentum Magnitude of momentum Calculation: Direction (degrees) Calculation: Before Collision Trial 4 Mass Ball 1 _______ kg Mass Ball 2 _________ kg Component Velocities v x (m/s) v y (m/s) v x (m/s) v y (m/s) Component Momenta p x (kgm/s) p y (kgm/s) p x (kgm/s) p y (kgm/s) Total Momentum in each direction Total p x momentum Calculation: Total p y momentum Calculation: Overall momentum Magnitude of momentum Calculation: Direction (degrees) Calculation: After Collision Trial 4 Mass Ball 1 _______ kg Mass Ball 2 _________ kg v x (m/s) v y (m/s) v x (m/s) v y (m/s) © Copyright 2017 Michigan Virtual Revised 5/18/2020 Page 4

Component Velocities Component Momenta p x (kgm/s) p y (kgm/s) p x (kgm/s) p y (kgm/s) Total Momentum in each direction Total p x momentum Calculation: Total p y momentum Calculation: Overall momentum Magnitude of momentum Calculation: Direction (degrees) Calculation: Analysis: 1. For each trial, determine the total momentum in the x-direction and the total momentum in the y-direction before and after the trial. How do these values compare? Do they make sense in terms of the law of conservation of momentum? (4 points) Total p x before (kgm/s) Total p x after (kgm/s) Total p y before (kgm/s) Total p y after (kgm/s) Trial 1 Trial 2 Trial 3 Trial 4 2. Was momentum conserved whether the collision was elastic or inelastic? If there was a difference, was the difference significant enough to state that momentum is not conserved for certain types of collisions? (2 points) 3. Predict whether the conservation of momentum will change or be the same when a third ball is added to the simulation. (2 points) 4. Test your prediction by adding a third ball to the simulation. Was your prediction accurate or did you find something unexpected? Explain. (2 points) © Copyright 2017 Michigan Virtual Revised 5/18/2020 Page 5