Chapter 6

A 1-N apple falls to the ground. The apple hits the ground with an impact force of about: A. 1 N B. 2 N C. 4 N D. 9.8 N E. not enough information given to say

d. not enough information given to say

Momentum is transferred to the ground when an apple falls on it. The momentum absorbed by the ground is: A. negligible compared to the momentum of the apple B. greater than that of the apple only if the apple bounces C. greater than that of the apple in all cases D. None of these

B. Greater than that of the apple only if the apple bounces

A freight train rolls along a track with considerable momentum. If it rolls at the same speed but has twice as much mass, its momentum is: a. zero b. doubled c. quadrupled d. unchanged

B. doubled

Two objects have the same size and shape, but one is much heavier than the other. When they are dropped simultaneously from a tower, they reach the ground at the same time, but the heavier one has a great: A. speed B. acceleration C. momentum D. all of these E. none of these

C. momentum

A 1000-kg car moving at 10 m/s breaks to a stop in 5 s. The average breaking force is: A. 1000 N B. 2000 N C. 3000 N D. 4000 N E. 5000N

B. 2000 N

Two billiard balls having the same mass and speed roll towards each other. What is their combined momentum after they meet? A. 0 B. half the sum of their original momentum C. twice the sum of their original momentum D. impossible to determine without additional information

A. 0

A ball has a momentum of 12 kg m/s. Whats the balls speed? A. 3 m/s B. 4 m/s C. 12 m/s D. 48 m/s E. None of these

A. 3 m/s

Padded dashboards in cars are safer in an accident than non-padded ones an occupant hitting the dashboard has : A. Increased time of impact B. Decreased time of impact C. Decreased Impulse D. increased momentum

A. increased time of impact

A 1-kg chunk of putty moving at 1 m/s collides with and sticks to a 5-kg bowling ball initially at rest. The bowling ball and putty then move with a momentum of : A. 0 kg m/s B. 1 kg m/s C. 2 kg m/s D. 5 kg m/s E. more than 5 kg m/s

B. 1 kg m/s

A 1-kg glider and a 2-kg glider both slide toward each other at 1 m/s on an air track. They collide and stick. The combined mass moves at: A. 0 m/s B. 1/2 m/s C. 1/3 m/s D.1/6 m/s E. 1.5 m/s

C. 1/3 m/s

A 1-kg chunk of putty moving at 1 m/s collides with and sticks to a 5-kg bowling ball that is initially at rest on a frictionless surface. The speed of the putty thereafter is: A. 1/4 m/s B. 1/5 m/s C. 1/6 m/s D. Impossible to solve with the information given

C. 1/6 m/s

A ball is moving at 3 m/s and has a momentum of 48 kg m/s. What is the balls mass? A. 4 kg B. 12 kg C. 16 kg D. 48 kg E. None of these

C. 16 kg

A 5-kg fish swimming at a speed of 1 m/s swallows an absent-minded 1-kg fish at rest. The speed of the larger fish after this lunch is: A. 1/2 m/s B. 2/5 m/s C. 5/6 m/s D. 6/5 m/s E. 1 m/s

C. 5/6 m/s

A 5000-kg freight car runs into a 10,000-kg freight car at rest. They couple upon collision and move with a speed of 2 m/s. What was the initial speed of the 5,000-kg car? A. 4 m/s B. 5 m/s C. 6 m/s D. 8 m/s E. none of these

C. 6 m/s

When you jump from an elevated position you usually bend your knees upon reaching the ground. By doing this, you make the time of the impact about 10 times as great as for a stiff-legged landing. In this way the average force your body experiences is: A. less than 1/10 as great B. more than 1/10 as great C. about 1/10 as great D. about 10 times as great

C. about 1/10 as great

According to the impulse momentum equation Ft=change in (mv), a person will suffer less injury falling on a wooden floor which "gives" than on a more rigid cement floor. The "F" in the above equation stands for the force exerted on the: A. only the person B. only the floor C. either the force on the person or the force on the floor D. the sum of the force on the person

C. either the force on the person or the force on the floor

A karate expert executes a swift blow and breaks a cement block with her bare hand. the magnitude of the force experienced by her hand is: A. zero B. less than the force applied to the cement block C. identical to the force applied to the block D. more than the force applied to the block E. impossible to predict without additional information

C. identical to the force applied to the block

A rifle of mass 2 kg is suspended by strings. The rifle fires a bullet of mass 0.01 kg at a speed of 200 m/s. the recoil velocity of the rifle is about: A. 0.001 m/s B. 0.01 m/s C. 0.1 m/s D. 1 m/s E. None of these

D. 1 m/s

A large heavy truck and a small baby carriage roll down a hill. Neglecting friction at the bottom of the hill, the baby carriage will have a greater: A. Speed B. Acceleration C. Momentum D. All of these E. None of these

E. Non of these