1. SMDEP Physics Conservation of Linear Momentum, Collisions, Center of Mass

2. Ch 9, #46: what is the speed? 1.37.6 m/s 2.20.3 m/s 3.9.7 m/s 4.76.8 m/s 5.Other 6.Didn’t finish

3. Ch 9, #54: direction of 1 st ball, speeds of both balls 1.x direction, v1’ = 2 m/s, v2’ = 3.7 m/s 2.-x direction, v1’ = 2 m/s, v2’ = 3.7 m/s 3.x direction, v1’ = 3.7 m/s, v2’ = 2 m/s 4.-x direction, v1’ = 3.7 m/s, v2’ = 2 m/s 5.Other 6.Didn’t finish

4. Ch 9, #61: location of center of mass 1.At the nitrogen atom 2.At the center of the equilateral triangle 3.0.03 nm from the center of the equilateral triangle, towards the nitrogen 4.0.7 nm from the center of the equilateral triangle, towards the nitrogen 5.Other 6.Didn’t finish

5. Ch 9, #86: what is the height? 1.9.3 m 2.0.7 m 3.6.5 m 4.1.1 m 5.Other 6.Didn’t finish

6. Attendance: When I was little I wanted to be a… 1.Doctor 2.Lawyer 3.Astronaut 4.Firefighter/Police Officer 5.Politician 6.Professional Athlete 7.Other

7. Suppose a bowling ball and a ping-pong ball are rolling towards you. Both have the same momentum, and you exert the same force to stop each of them. How do the time intervals required to stop them compare? 1.Less time to stop the ping-pong ball 2.Same time to stop the ping-pong ball 3.More time to stop the ping-pong ball

8. A cart moving at speed v collides with an identical stationary cart on an airtrack. The carts stick together and continue moving after the collision. What is their speed after colliding? 1.v 2.v/2 3.0 4.Need more information

9. A basketball is dropped from rest and falls a height of 1 m. It bounces off the Earth and returns to a height of 1m. The collision was: 1.Elastic 2.Inelastic 3.Totally inelastic 4.Explosive 5.Need more information

10. A compact car and a large truck collide head-on and stick together. Which undergoes the larger change in momentum? 1.Car 2.Truck 3.Same for both 4.Can’t tell without knowing final velocity

11. Two identical objects collide inelastically. Can all the initial kinetic energy in the collision be transformed into other forms of energy? 0 of 5 :10 1.Yes, for certain conditions on the initial velocities 2.Yes, provided the objects are soft enough 3.No, this violates a fundamental law of physics 4.None of the above

12. Suppose a bowling ball and a ping-pong ball are rolling towards you. Both have the same momentum, and you exert the same force to stop each of them. How do the distances required to stop them compare? 0 of 5 :10 1.Less distance to stop the ping-pong ball 2.Same distance to stop the ping-pong ball 3.More distance to stop the ping-pong ball

13. Where is the center of mass of the Earth-Sun system? 0 of 5 :10 1.Halfway between the Earth and the Sun 2.Near the center of the Earth 3.Near the center of the Sun 4.Unable to estimate