chapter 6 physics

A 5000 kg freight car moving at 2 m/s collides with a 10,000 kg freight car at rest. They couple upon collision and move away at

2 m/s

The average breaking force of 1000 kg car moving at 10 m/s braking to stop in 5 seconds is

2000 N

A 5kg fish swimming at 1 m/s swallows an absent-minded 1 kg fish at rest. The speed of the larger fish after lunch is

5/6 m/s

A motorcycle of mass 100 kg slowly rolls off the edge of a cliff and falls for three seconds before reaching the bottom of a gully. Its momentum upon hitting the ground is A. 3000 kg m/s B. 2000 kg m/s C. 1,000 kg m/s D. 9000 kg m/s

A. 3000 kg m/s

The speed of a 4 kg ball with momentum of 12 kg is? A. 12 m/s B. 3 m/s C. 4 m/s

B. 4 m/s

When a boxer moves into an oncoming punch, the force experienced is A. decreased B. increased

B. increased

A Billy steps off a hovering high-flying helicopter and fall through the air, he experiences

an impulse an increasing speed a decreasing acceleration

A karate chop is more effective if one's hand

bounces upon impact

A cannon recoils while firing a cannonball. The speed of the cannon's recoil is relatively small because the

cannon has much more mass than the cannonball

The force that accelerates a rocket is outer space is exerted on the rocket by the

exhaust gases

A heavy truck and a small car rolling down a hill at the same speed are forced to stop in the same amount of time. Compared with the force that stops the car, the force needed to stop the truck is

greater

A softer landing occurs when a falling object bounces from a surface

in an extended time

You're driving down the highway and a bug splatters on your windshield. Which undergoes the greater change in momentum during the time of contact?

the car and the bug

Two identical freight cars roll without friction (one at 1 m/s, the other at 2 m/s) towards each other on a level track. They collide, couple together and roll away in the direction of

the faster car

Two identical objects in outer space, one moving at 2 m/s, the other 1 m/s have a head-on collision and stick together. Their combined speed after the collision is

0.5 m/s

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

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

1/3 m/s

Whether a truck comes to a stop by crashing into a haystack or a brick wall, the stopping force is A. greater with the brick wall B. greater with the haystack C. both the same D. can not be determined

A. greater with the brick wall

The catch a fast-moving ball, you extend your hand forward before contact with the ball and let it ride backward in the direction of the ball's motion. Doing this reduces the force of contact on your hand principally because A. time of contact is increased B. time of contact is decreased C. relative velocity is less D. force of contact is reduced

A. time of contact is increased

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. twice B. four times as much C. unchanged D. zero

A. twice

Which has greater momentum when moving? A. either of these depending on speed B. a container ship C. Both

C. Both

If you can't avoid being hit by a fast-moving object, you'll suffer a smaller contact force if you an extend that force over a A.both are the same B. shorter time C. longer time

C. longer time

If several ball are thrown straight up with different initial speeds, the quantity that will hve the same value along their paths is their A. initial momentum B. maximum height C. time travel D. acceleration E. none of the above

D. acceleration

A car traveling along the highway brakes to stop over a certain distance. More braking force is required if the car has A. less stopping distance B. more mass C. more momentum D. all of the above

D. all of the above

The force on a dropped apple hitting the ground depends upon A. the speed of the apple just before it hits B. whether or not the apple bounces C. the time of contact with the ground D. all of the above

D. all of the above

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 likely have A. can not be determined B. more momentum C. about the same momentum D. less momentum

D. less momentum

if all people, animals, trains and trucks all over the world began to walk or run towards the east (opposite the direction of Earth's spin) then

Earth would spin slower

A falling 1 N apple hits the ground with a force of about

can not be determined

If a monkey floating in outer space throws hi hat away, the hat and the monkey will both

move away from each other, but a different speeds