Physics Review Work and Energy

Mac and Tosh run up the same hill.  Mac has twice the mass as Tosh.  Tosh climbs up the hill in one-half the time as Mac.  In this situation, _____.

• Mac and Tosh do the same amount of work, but Mac has a greater power rating
• Mac does more work than Tosh, but Tosh has a greater power rating
• Tosh does more work than Mac, but Mac has a greater power rating
• Mac does more work than Tosh, but they have the same power rating

Tags

NGSS.HS-PS3-2

In a physics lab, a 60-kg student runs up a 2.0-meter tall flight of stairs in 1.5 seconds.  The student's power rating is approximately _____ W

• 180
• 800
• 450
• 200

Which of the following is true of an object whenever work is done on the object?

• The object moves.
• The object accelerates.
• The forces acting upon the object are balanced.
• The forces acting upon the object are unbalanced.

Tags

NGSS.HS-PS2-1

A rightward force acts upon an object that is moving to the left. Such a force does _____.

• positive work
• negative work
• no work at all

The rate at which work is done is referred to as _____.

• energy
• momentum
• power
• potential energy

A sledder has 600 J of potential energy and 200 J of kinetic energy at one point on a steep hill. How much kinetic energy will the sledder have at the bottom of the hill? (Assume negligible air resistance and friction.)

• 200 J
• 600 J
• 400 J
• 800 J

Tags

NGSS.HS-PS3-1

An object possesses 45 J of total energy. A force does -25 J of work upon the object. How much energy will the object now possess?

• 20 J
• 45 J
• 70 J
• 35 J

Tags

NGSS.HS-PS3-1

An object has 25 J of kinetic energy and 15 J of potential energy. Work is done on the object leaving it with 50 J of kinetic energy and 15 J of potential energy. How much work is done on the object?

• 45 J
• 30 J
• 25 J
• . 40 J

Tags

NGSS.HS-PS3-1

A child lifts a box up from the level floor. The child then carries the box with constant speed to the other side of the room and puts the box down. How much net work does he do on the box while walking across the floor at constant speed?

• zero J
• more than zero J
• more information needed to determine

A teacher pushes against a wall for a couple of hours and becomes exhausted.   This is an example of _________ work being done.

• positive
• negative
• no