Work and Energy

In which scenario is work = 0 J ?

• Pushing a stationary wall

• Pulling a trolley car

• Pushing a book across the table

• Dropping a set of keys from a height, h.

Power depends on force and speed.

• True

• False

If the net work done on an object is positive, what can you conclude about the object's motion?

• The object is speeding up.

• The object is moving with a constant velocity.

• The object is slowing down.

• The object is at rest; its position is constant.

When a body falls freely towards the earth, then its total energy

• (a) increases

• (b) decreases

• (c) remains constant

• (d) first increases and then decreases

Tags

NGSS.MS-PS3-2

NGSS.MS-PS3-5

When a coil spring is compressed, the work is done on the spring. the elastic potential energy

• Increases

• Decreases

• Disappears

• Remain unchanged

Tags

NGSS.MS-PS3-2

Mechanical energy of a body includes

• Kinetic energy only

• Potential energy only

• kinetic energy and potential energy

• None of these

Tags

NGSS.MS-PS3-2

If speed of a car becomes 2 times, its kinetic energy becomes

• 4 times

• 8 times

• 16 times

• 12 times

Tags

NGSS.MS-PS3-1

What is a force?

• a push or a pull
• a force that slows or stops an object in motion

What is the unit used to measure work?

• Joule
• Watt
• Newton
• Pascal

Tags

NGSS.MS-PS3-5

What kind of energy is in a moving skateboard?

• Potential
• Kinetic

Tags

NGSS.MS-PS3-1

NGSS.MS-PS3-5