physical science hw chapter 3

3 m/s

20. A 4-kg ball has a momentum of 12 kg.m/ s. What is the ball's speed? 3 m/s 4 m/s 12 m/s 48m/s none of these

12 kg

21. A ball is moving at 4 m/ s and has a momentum of 48 kg.m/ s. What is the ball's mass? 4 kg 12 kg 48 kg 192 kg none of these

6 m/s

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

doubled

A freight train rolls along a track with considerable momentum. If it were to roll at the same speed but had twice as much mass, its momentum would be zero doubles quadrupled unchanged

twice as much

An object lifted 10 m gains a certain amount of potential energy. If it is lifted 20 m, it's gain in potential energy is less the same twice as much four times as much more than four times as much

the change in momentum

It is correct to say that impulse is equal to momentum the change in momentum the force multipled by the distance the force acts all of the above

2000N

a 1000-kg car moving at 10 m/s that brakes to a stop in 5 s has an average braking force of? 1000N 2000N 3000N 4000N 5000N

80 J

a 2-kg mass weights 20 N and is held 4 m above the ground. its potential energy relative to the ground is? 8 J 20 J 60 J 80 J

all of the above

a car traveling along the highway needs a certain amount of braking force to stop. more braking force is required when the car has more mass more momentum less stopping distance

momentum

a heavy truck and a small truck roll down a hill. neglecting friction, at the bottom of the hill the heavy truck has greater speed acceleration momentum all of the above

momentum

an object in motion will continue in motion with acceleration impulse momentum

location

an object may have potential energy because of its speed momentum acceleration location

speed

from the same height you simultaneously drop a lightweight tennis ball and a heavyweight bowling ball. when they hit the floor they have the same speed force momentum

kinetic energy

if a charging rhinoceros has momentum, it must also have potential energy kinetic energy work

time of catch is increased

in order to catch a fast-moving softball with your bare hand, you extent your hand forward just before the catch and then let the ball ride backward with your and. doing this reduces the catching force because the relative velocity is less relative velocity is more time of catch is increased time of the catch is decreased