Summative-Work, Energy and Power

The amount of potential energy possessed by an

elevated object is equal to which of the following?

• the power used to lift it

• the distance it is lifted

• the force needed to lift it

• the work done in lifting it

A 10 kilogram object and a 5 kilogram object

are released simultaneously from a height of

50 meters above the ground.

Which of the following will be different for the objects after they fall freely for 2 seconds?

• their displacements

• their speeds

• their kinetic energies

• their accelerations

The direction of a moving car changes while its speed remains constant.

Which quantity related

to the car's motion remains the same?

• velocity

• displacement

• kinetic energy

• momentum

If the motor of an electric fan converts 24,000 Joules of electric energy every minute, what is the

power of the fan's motor?

• 60 Watts

• 100 Watts

• 400 Watts

• 650 Watts

Which term is defined as the

rate at which work

is done?

• mechanical energy

• momentum

• power

• velocity

How many seconds

would it take a machine to do

5000 Joules of work

if the power of the

machine is 100 watts?

A ball of mass 0.20 kg rolls off of a tabletop at a speed of 2.00 m/s. The table is 1.25 m high. Assume that the potential

energy at the floor is zero. While the ball is in the air after it leaves the table, what happens to the relationship between its

kinetic and potential energies?

• Both its kinetic energy and potential energy

  increase.

• Both its kinetic energy and potential energy

  remain constant.

• Its kinetic energy increases, while its potential

  energy decreases.

• Its kinetic energy decreases, while its potential

  energy increases.

When a 5 kilogram mass is raised vertically

2 meters from the ground, what is its gain in

potential energy, in Joules?

Just enter the answer without units.

The diagram below represents a 2 kilogram object on a frictionless track. The object is released from

rest at point A, and at point E its gravitational potential energy is 0. What is the gravitational potential energy of the object at point A?

• 20 J

• 80 J

• 700 J

• 800 J

The diagram below represents a 2 kilogram object on a frictionless track. The object is released from

rest at point A, and at point E its gravitational potential energy is 0. What is the gravitational potential energy of the object at point F?

• 10 J

• 20 J

• 100 J

• 200 J