Day 64: Collision Video Analysis
AP Physics C: Students used Logger Pro to do video analysis of 2 colliding dynamics carts. Each student in a lab group was responsible for analyzing a different video, then share out results and look for patterns.
The videos are here: Live Photo Physics Colliding Carts. We used videos #31, 32, 34, and 45.
Students are already familiar with collisions from physics last year. So this year, we are focusing on how the center of mass moves and how the carts move relative to the center of mass.
- Create a graph showing the position of each cart and the position of the center of mass over time. Find slopes.
- Create a second graph showing the position of each cart RELATIVE TO the center of mass over time. Find slopes.
- Determine the total momentum of the system before and after the collision.
- Determine the total kinetic energy of the system before and after the collision.
- Determine the fractional change in internal energy of the system as a result of the collision.
Compare/contrast your results with the others in your group:
- Does the velocity of the center of mass remain constant always/sometimes/never?
- In the center of mass reference frame, what do you notice about before/after velocities of each cart for elastic and inelastic collisions?
- Is momentum conserved always/sometimes/never?
- Is kinetic energy conserved always/sometimes/never?
NGSS Science and Engineering Practices:
#4. Analyzing and interpreting data
#5. Using mathematics and computational thinking
#7. Engaging in argument from evidence