question

W =

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Force x Distance

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The work done in pushing a TV set a distance of 2 m with an average force of 20 N is

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40 J

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The work you do when pushing a shopping cart twice as far while applying the same force is

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twice as much

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The work you do when pushing a shopping cart twice as far while applying twice the force is

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four times as much

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The work you do when pushing a shopping cart a given distance while applying twice as much force is

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twice as much

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No work is done by gravity on a bowling ball that rolls along a bowling alley because

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the force on the ball is at right angle's to the balls motion

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A 1000-kg car and a 2000-kg car are hoisted to the same height. Raising the more massive car requires

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twice as much work

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The unit kilowatt-hour is a unit of

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energy

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One kilowatt-hour represents

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3.6 million joules

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Which task requires more work?
lifting the 25-kg sack 4 meters
lifting the 50-kg sack 2 meters

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both the same

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The amount of work done on a heavy box carried by Nellie across a room at a constant speed

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is none

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If you do work on a skateboard loaded with friends in one-third the usual time, you expend

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three times the usual power

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The power expended doing 100 J of work in 50 s is

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2 W

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The power required to exert 4-N force over 3 meters in 2 seconds is

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6 W

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Both a 50-kg sack is lifted 2 meters from the ground and a 25-kg sack is lifted 4 meters in the same time. The power expended in raising the 50-kg sack is

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the same

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A toy elevator is raised from the ground floor to the second floor in 20 seconds. The power needed using 1000 J of work, is

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50 W

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An object has gravitational potential energy due to its

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location

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Relative to an initial height, an object raised twice as high has a gravitational potential energy

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twice as much

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A crate of grapes lifted 10 meters gains 200 J of potential energy. If the same crate is instead lifted 20 meters, its gain in potential energy is

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twice as much

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When a drawn bow of potential energy 40 J is fired, the arrow will ideally have a kinetic energy

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of 40 J

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A clerk can lift cylindrical packages 1 meter vertically, or can roll them up a 2-meter-long ramp to the same elevation. With the ramp, the applied force required is about

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half as much

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A 2-kg ball is held 4 m above the ground. Relative to the ground its potential energy is

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80 J

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A 2-kg box of taffy candy has 40 J of potential energy relative to the ground. Its height above the ground is

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2 m

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The ram of a pile driver drops onto the top of an iron beam, driving it partway into the ground. The distance that the beam sinks into the ground depends on the

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all of the above; initial energy of the ram, kinetic energy of the ram when it first hits the beam, initial height of the ram

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An object that has kinetic energy must be

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moving

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Two identical golf carts move at different speeds. The faster cart has twice the speed and therefore has

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four times the kinetic energy

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

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accelerations

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A melon is tossed straight upward with 100 J of kinetic energy. If air resistance is negligible the melon will return to its initial level with a kinetic energy of

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100 J

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A melon is projected into the air with 100 J of kinetic energy in the presence of air resistance. When it returns to its initial level its kinetic energy is

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less than 100 J

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Danny Diver weighs 500 N and steps off a diving board 10 m above the water. Danny hits the water with kinetic energy of

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5000 J

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Which has greater kinetic energy?

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a car of half the mass traveling at 60 km/hr

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Neglecting air resistance, Sammy Smarts on a high ladder releases a ball that strikes the ground with 100 J of kinetic energy. If he were to instead throw the ball straight upward, it will soon reach the ground with a kinetic energy of

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more than 100 J

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If a Ping-Pong ball and a golf ball both move in the same direction with the same amount of kinetic energy, the speed of the Ping-Pong ball must be

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more than the golf ball

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Two identical particles move toward each other, one twice as fast as the other. Just before they collide, one has a kinetic energy of 25 J and the other 50 J. At this instant their total kinetic energy is

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75 J

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When Joshua brakes his speeding bicycle to a stop, kinetic energy is transformed to

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heat