Work, Energy, Power

If a system is isolated, the total energy of the system

• Increases constantly.

• Decreases constantly.

• Is constant.

• Depends on the work done on the system.

• Depends on the work done by the system.

Tags

NGSS.HS-PS3-1

NGSS.HS-PS3-2

Which of the following is defined as an energy transfer?

• kinetic energy

• work

• potential energy

• chemical energy

Tags

NGSS.MS-PS3-5

The unit of work is

• watt

• hertz

• joule

• pascal

A 6.5 kg object encounters a changing force that is graphed Vs distance below. How much work was done on the object by this force?

• 30 J

• 60 J

• 70 J

• 80 J

Each of the boxes shown is pulled for 10 m across a level, frictionless floor by the force given. Which box experiences the greatest change in its kinetic energy?

• A

• B

• C

• D

• E

Tags

NGSS.HS-PS2-1

Rank in order, from largest to smallest, the gravitational potential energies of the balls.

• 1 > 2 = 4 > 3

• 1 > 2 > 3 > 4

• 3 > 2 = 4 > 1

• 3 > 2 > 4 > 1

Tags

NGSS.HS-PS3-1

NGSS.HS-PS3-2

Starting from rest, a marble first rolls down a steeper hill, then down a less steep hill of the same height. Ignoring friction, for which is it going faster at the bottom?

• Faster at the bottom of the steeper hill

• Faster at the bottom of the less steep hill

• Same speed at the bottom of both hills

• Can’t say without knowing the mass of the marble

Tags

NGSS.HS-PS2-1

NGSS.HS-PS2-4

A small child slides down the four frictionless slides A–D. Rank in order, from largest to smallest, her speeds at the bottom.

• vD > vA > vB > vC

• vD > vA = vB > vC

• vC > vA > vB > vD

• vA = vB = vC = vD

Tags

NGSS.HS-PS2-1

NGSS.HS-PS3-1

NGSS.HS-PS2-4

Four students run up the stairs in the time shown. Which student has the largest power output?

• A

• B

• C

• D

You are traveling along a freeway at 65 mi/h; your car has kinetic energy. You suddenly skid to a stop because of congested traffic. What happened to the kinetic energy your car just had?

• It is all in internal energy in the road

• It is all in internal energy in the tires

• Some of it has transformed to internal energy for the tires and the road, and some of it transferred away by sound energy and thermal energy into the air.

• It was destroyed

Tags

NGSS.HS-PS3-4