1. In boxing, fighters wear padded gloves to protect their hands. Which statement explains why a fighter’s hands need protection?
A. There is an equal and opposite velocity impact the hand.
B. There is an equal and opposite acceleration impact the hand.
C. There is an equal and opposite momentum impacting the hand.
D. There is an equal and opposite force impacting the hand.

2. Two balls collide. Under which circumstances will they exert equal and opposite forces on each other?
A. If the sustem is closed
B. in all situations
C. If both are moving at the same speed when they collide
D. if they have the same mass

3. In a closed system, how does an increase in mass change the velocity of an impacted object?
A. Velocity decreases to conserve momentum.
B. Velocity may increase or decrease depending on acceleration.
C. Velocity may increase or decrease depending on force.
D. Velocity increases to conserve momentum.

4. Which of the following provides the correct equation for calculating the momentum of an object?
A. p= mv
B. m= DV
C. F= ma
D. m= vp

5. An object with a mass of 50 kg is moving at a velocity of 2 m/s. What is the momentum of the object?
A. 2 kg*m/s
B. 0.04 kg*m/s
C. 100 kg*m/s
D. 25 kg*m/s

6. A large train car moving along a horizontal track rolls into a smaller stationary train car, causing the cars to attach. Which statement best describes the motion of the cars after the connection?
A. The train cars move in the opposite directions from each other.
B. The train cars move together in the opposite direction the large car was moving.
C. The train cars move together in the direction the large car was moving.
D. The train cars both stay stationary.

7. Which equation correctly represents conservation of momentum for two colliding objects?
A. m1a1+m2a2=0
B. m1v1-m2v2=0
C. m1a1-m2a2=0
D. m1v1+m2v2=0

8. How can the sum of two vectors be found?
A. by drawing the vectors perpendicular to each other
B. by adding the numbers representing the vectors' magnitudes
C. by subtracting the numbers of the vectors' magnitudes
D. by drawing the vectors one right after the other

9. How could a closed system be changed without changing the net force on that system?
A. decrese the acceleration only
B. increase the mass and decrease the acceleration by the same numeric values
C. decrease the acceleration and decrease the mass by the same numeric values
D. increase the mass only

10. Which phrase best describes acceleration?
A. the produce of mass and velocity
B. the change in position over time
C. the product of force and distance traveled
D. the change in velocity over time

11. A ball rolls down a hill at constant velocity. Which of the following conditions must be true?
A. The ball will accelerate as gravity pulls it down the hill.
B. The ball has no net force acting on it.
C. There are no forces acting on the ball.
D. The momentum of the ball increases over time.

12. In an experiment, objects 1 and 2 with masses m1 and m2, respectively, collide with each other. The objects have initial velocities v1i and v2i and final velocities v1f and v2f, respectively. Which result would prove conservation of momentum?
A. m1v1i+m2v2i=m1v1f+m2v2f
B. m1v1i+m1v1f=m2v2i+m2v2f
C. m1v1i+m2v2i+m1v1f+m2v2f>0
D. m1v1i+m2v2i+m1v1f+m2v2f=0