Physics Test 4 Multiple Choice

(c) 12 kg m/s

A 4 kg ball has a speed of 3 m/s. What is the ball's momentum? (a) 12 kg m/s (b) 4 m/s (c) 12 kg m/s (d) 48 m/s (e) none

(b) 40 J

A bow is pulled back and stretched so that it has 40 J of potential energy. When the bow is released and an arrow begins moving, the arrow will ideally have a kinetic energy of (a) more than 40 J (b) 40 J (c) less than 40 J

(d) 16 times the KE

A car moves 4 times as fast as another identical car. Compared to the slower car, the faster car has (a) 4 times the KE (b) 8 times the KE (c) 12 times the KE (d) 16 times the KE

(a) power

A job is done slowly, while an idenitical job is done quickly. Both jobs require the same amount of work, but different amounts of (a) power (b) energy (c) both (e) none

(b) less than the speed of the bullet

A rifle recoils (moves back in the opposite direction) from firing a bullet. The speed of the rifle's recoil is (a) equal to the speed of the bullet (b) less than the speed of the bullet (c) greater than the speed of the bullet (d) dependent on the potential energy of the bullet

(d) moving

An object that has kinetic energy must be (a) at rest (b) at an elevated position (c) falling (d) moving (e) none

(d) location

An object that has potential energy may have this energy because of its (a) acceleration (b) speed (c) momentum (d) location (e) none

(c) 2 W

Do 100 J of work in 50 s and your power output is (a) 1/4 W (b) 1/2 W (c) 2 W (d) 4 W (e) more than 4 W

(b) twice as much work

If you push an object twice as far while applying the same force you do (a) four times the work (b) twice as much work (c) same amount of work

(a) the change in momentum

It is correct to say impulse is equal to (a) the change in momentum (b) momentum (c) the force multiplied by the distance the force acts (d) all the above (e) none

(e) A and C

Padded dashboards in cars are safer in an accident than nonpadded ones because an occupant hitting the dash has (a) increased time of impact (b) decreased impulse (c) decreased impact force (d) A and B (e) A and C

(d) time of impact is increased

The best way to catch an egg without breaking it is move your hand backwards with the egg. When your hand moves with the incoming egg, the (a) time of impact is decreased (b) force of impact is increased (c) impulse is increased (d) time of impact is increased (e) none

(b) 0 kg m/s

Two billiard balls having the same mass roll toward each other, each moving at the same speed. What is the combined momentum of the two balls? (a) 10 kg m/s (b) 0 kg m/s (c) more information needed

(b) momentum

Two objects, A and B, have the same size and shape, but A is twice as heavy as B. When they are dropped simultaneously from a tower, they reach the ground a the same time, but A has a greater (a) acceleration (b) momentum (c) speed (d) all (e) none

(b) twice as much potential energy

When an object is raised above the ground it gains a certain amount of potential energy. If the same object is raised twice as high it gains (a) four times as much potential energy (b) twice as much potential energy (c) neither of these

(a) long time

When you are in the way of a fast moving object and can't get out of the way, you will suffer a smaller force of impact if you decrease its momentum over a (a) long time (b) short time (c) same outcome either way

(a) the dog

Which has more momentum, a truck parked in a lot or a dof walking across the lot? (a) the dog (b) the truck (c) they have the same momentum (d) more information needed

(c) both require an equal amount of work

Which requires more work: lifting a 50 kg sack vertically 2 meters of lifting a 25 kg sack vertically 4 meters? (a) lifting the 50 kg sack (b) lifting the 25 kg sack (c) both require an equal amount of work

(c) both the same

You're driving down the highway and a bug spatters into your windshield. Which undergoes the greater change in momentum? (a) the bug (b) your car (c) both the same