Conceptual Energy Review

A pulley system can only change direction; it can't multiply forces as well.

• true
• false

When we carry an object across a room, without lifting it or setting it down, we do no physical work on it. 

• true
• false

More power is needed to carry a heavy suitcase slowly up a flight of stairs than to carry the suitcase quickly up the same flight of stairs.

• true
• false

The unit of work is called the joule

• true
• false

The energy an object has by virtue of its motion is its kinetic energy.

• true
• false

Tags

NGSS.HS-PS3-2

Cannonballs are launched from an airplane in the forward direction of motion. The momentum of the airplane will be:

• increased
• unchanged
• decreased

If the velocity of a moving object doubles, then what else doubles?

• kinetic energy
• momentum
• acceleration
• all of the above

A job is done slowly and and identical job is done quickly. Both jobs require the same amount of work but different amounts of: 

• power
• energy
• both energy and power
• none of the above

An object that has linear kinetic energy must be:

• at an elevated position
• moving
• at rest
• none of the above

Suppose a moving car has 2000 J of kinetic energy. If the car's speed doubles, how much kinetic energy would it then have?

• 1000 J
• 6000 J
• 8000 J
• 4000 J