A .001Kg Bullet Is Fired Into a 2.5Kg Ballistic Pendulum. the Pendulum Moves up .35M

Science Olympiad

Physics Lab

Week 1

1. Albert Einstein is floating on a boat in the middle of a pool filled with heavy water. He has been banished to the middle of the pool for not accepting quantum mechanics. Einstein wants to paddle to the edge of the pool so he can get out and tell the other scientists that “God does not play dice with the universe.” Unfortunately, the boat he is in is carrying dense uranium blocks and the pool is filled to the brim and if he paddles the disturbance will cause some of the precious water to spill from the pool. How can Einstein make it to the side of the pool without losing any heavy water?

2.

A .001kg bullet is fired into a 2.5kg ballistic pendulum. The pendulum moves up .35m.

A. What is the velocity of the bullet before it strikes the pendulum?

B. What is the momentum of the bullet before it strikes the pendulum?

C. What is the kinetic energy of the bullet before it strikes the pendulum?

D. What is the kinetic energy of the bullet pendulum system after the bullet is lodged in the pendulum?

E. How much kinetic energy was lost in the collision?

3.

The mass m accelerates downwards at 5m/s2. What is the mass of mass m?

4. The graph to the right is a plot of position versus time. For which labeled region is the velocity positive and the acceleration negative?

A. A
B. B
C. C
D. D
E. E

5. Three balls roll over the three paths shown. What happens?

A. Ball 1 takes the least time

B. Ball 2 takes the least time

C. Ball 3 takes the least time

D. All three balls take the same time

6. In a rescue attempt, a hovering helicopter drops a life preserver to a swimmer being swept downstream by a river current of constant velocity v. The helicopter is at a height of 9.8 m. The swimmer is 6.0 m upstream from a point directly under the helicopter when the life preserver is released. It lands 2.0 m in front of the swimmer. How fast is the current flowing? Neglect air resistance.

A. 13.7 m/s
B. 9.8 m/s
C. 6.3 m/s
D. 2.8 m/s
E. 2.4 m/s

7. A pendulum is attached to the ceiling of an elevator car. When the car is parked, the pendulum exhibits a period of 1.00 s. The car now begins to travel upward with an upward acceleration of 2.3 m/s2 . During this part of the motion, what will be the approximate period of the pendulum?

A. 0.80 s
B. 0.90 s
C. 1.00 s
D. 1.10 s
E. 1.20 s

8. Two ice skaters, a 200 lb man and a 120 lb woman, are initially hugging on a frictionless level ice surface. Ten seconds after they push off from each other, they are 8.0 m apart. How far has the woman moved in that time?

A. 8.0 m
B. 6.5 m
C. 5.0 m
D. 4.0 m
E. 3.0 m

9. A gas contains a mixture of 4He and 20Ne atoms. If the average speed of the 4He atoms is vo, what is the average speed of the 20Ne atoms?

10. Air track car Z of mass 1.5 kg approaches and collides with air track car R of mass 2.0 kg. See the accompanying diagram. Car R has a spring attached to it and is initially at rest. When the separation between the cars has reached a minimum, then:

A. car R is still at rest.
B. car Z has come to rest.
C. both cars have the same kinetic energy.
D. both cars have the same momentum.
E. the kinetic energy of the system has reached a minimum.

11. The diagram below shows the velocity-time graph for two masses R and S that collided elastically. Which of the following statements is true?

I. R and S moved in the same direction after the collision.
II. The velocities of R and S were equal at the mid-time of the collision.
III. The mass of S was greater than the mass of R.

A. I only
B. II only
C. I & II only
D. II & III only
E. I, II, & III