# Review for Energy, Work, Power Test. Work is always done ? What is the definition of work? A force moves an object in the direction of the force.

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Review for Energy, Work, Power Test

Work is always done ? What is the definition of work? A force moves an object in the direction of the force

A 80N weight rest on a platform 2m high. The work done by the platform to support the weight is? W=Fxd Is it moving? No

A tennis ball is thrown upward. What increase as the ball rises? Potential or Kinetic? Potential when rises

Alyssa has done 20J of work to lift a 2kg box at a constant speed. If she drops it how fast will the box be going when it hits the ground? Moving so Kinetic Energy KE = ½ mv 2

A tennis ball is thrown in air where is the maximum kinetic energy? Before it loses the energy. When it first leaves the hand

Riley applies a force of 320N horizontally to the right against a 50kg box. The force of friction between the crate and the floor is 300N. If the box is pushed 2m, the total work done on the box is? Box is going one way and the friction is going another = displacement W= Fxd

Energy is the ability to work? Yes

Fountain shoots water at a height of 80m while its on. What is the initial velocity? PE=KE mgh= ½ mv 2 Cancel out the mass because it does not matter

What is the average power supplied by a 120kg dog running up a flight of stairs rising vertically 8m in 8.4s? P = W/t P = Fxd/t

If a vehicle has lots of power than? P = W/t So, the less amount of time it does to do work

The stairs in the main hall is 100m tall but if a bowling ball fell at the landing which is only 40m from base. What is the PE? PE= mgh Subtract the two heights because of the landing

Averie is moving at a constant velocity while carrying her puppy that weights 20N 1m across a level surface. What is the work done by the puppy? Is the puppy moving by itself?

A apple is moving 14m, 100J of work are done. What is the Force? W= Fxd

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