Work, Power and Energy

The work done in accelerating an object along horizontal surface is equal to the object's change in _____.

• kinetic energy

• momentum

• potential energy

• velocity

Which of the following is a scalar quantity?

• work

• energy

• power

• all of the above

Based on the table below, which machine has the greater power ouput?

Machine A - (amount of work) - 100 J - Time - 4 s

Machine B - (amount of work) - 500 J - Time - 10 s

Machine C - (amount of work) - 350 J - Time - 5 s

Machine D - (amount of work) - 450 J - Time - 15 s

• Machine A

• Machine B

• Machine C

• Machine D

As the time required for a person to do work increases, his power output

• decreases

• increases

• increases then decreases

• remains the same

As a ball falls freely,

• its kinetic energy decreases and potential energy decreases

• its kinetic energy decreases and potential energy increases

• its kinetic energy increases and potential energy decreases

• its kinetic energy increases and potential energy increases

Tags

NGSS.MS-PS3-1

NGSS.MS-PS3-2

NGSS.MS-PS3-5

A force when applied to a string stretches it. If the applied force is doubled, the potential energy of the spring will be

• doubled

• halved

• quadrupled

• same

The force that does no work on the object is

• friction

• force of gravity

• applied force

• horizontal component of the applied force

Unit of power.

Unit of Work

Tags

NGSS.HS-PS3-1

NGSS.HS-PS3-2

1 watt is equivalent to ______