Physical Science Ch 4 Homework

2 m

A 2-kg mass has 40 J of potential energy with respect to the ground. Approximately how far is it located above the ground?

40 J

A bow is drawn so that it has 40 J of potential energy. When fired, the arrow will ideally have a kinetic energy of

accelerations

A feather and a coin dropped in a vacuum fall with equal

created

Energy cannot be

2 W

Exert 100 J in 50 s and your power output is

work divided by time

Power is

16 times the KE

A car moves 4 times as fast as another identical car. Compared to the slower car, the faster car has

180 m

A car moving at 50 km/h skids 20 m with locked brakes. How far will the car skid with locked brakes if it is traveling at 150 km/h?

four times as far

A car that travels twice as fast as another when braking to a stop will skid

half as much

A clerk can lift containers a vertical distance of 1 m or can roll them up a 2-m-long ramp to the same elevation. With the ramp, the applied force required is about

0 J

A woman lifts a box from the floor. She then moves with constant speed to the other side of the room, where she puts the box down. How much work does she do on the box while walking across the floor at constant speed?

energy

An object at rest may have

moving

An object that has kinetic energy must be

location

An object that has potential energy may have this energy because of its

mass, height, and acceleration

Gravitational potential energy depends on which of the following?

momentum

If an object has kinetic energy, then it must also have ____________

twice the usual output

If you do work on an object in half the time, your power output is

twice as much work

If you push an object just as far while applying twice the force, you do

twice as much work

If you push an object twice as far while applying the same force, you do

on the wall

If you push for an hour against a stationary wall, you do no work

joule

What is the SI unit of energy?

heat

When a car is braked to a stop, its kinetic energy is transformed to

twice as much

When an object is lifted 10 m, it gains a certain amount of potential energy. If the same object is lifted 20 m, its potential energy gain is

the 60 km/h car

Which has greater kinetic energy, a car traveling at 30 km/h or a car of half the mass traveling at 60 km/h?

Both require the same amount of work.

Which requires more work: lifting a 50-kg sack vertically 2 m or lifting a 25-kg sack vertically 4 m?