1. Collisions and Explosions Pre-Lab Unit 9

2. 2 kinds of collisions - Inelastic and elastic

3. Make a prediction about the conservation of momentum and kinetic energy in both elastic and inelastic collisions.

4. What factors can you change and measure to test your prediction?
????

5. My suggestions: Mass of cart Velocity of each cart
Sticking together or not

6. After lab, define elastic and inelastic to see if your prediction and your data are correct!

7. Website: http://www.physics.uoguelph.ca/phyjlh/Fendt/phe/collision.htm

8. Collisions and Explosions Post-Lab Unit 9

9. Examples of Momentum Charts
A 40 kg girl rollerblades at 4 m/s toward her 20 kg dog, who is running at 7 m/s in the opposite direction. The dog leaps into the girl’s arms and they continue rolling together. Determine their velocity. m v
40 kg
20 kg
4 m/s
40 kg + 20 kg Vf
-7 m/s

10. 2) A 0.03 kg bullet travelling at 300 m/s ricochets off a wall at 100 m/s in the opposite direction. Determine the momentum transferred to the wall-earth system. m v
0.03 kg
300 m/s
-100 m/s
∆pw

11. FDt = mDv = Dp If there is a large impulse, the Dp will be great.
If there is a large force, there is a large acceleration, making Dv large
Large changes in p damage skin, bones, car bodies, etc…
Padding, follow through, seat belts, airbags reduce the change in momentum