Ch. 7 - Energy Assessment

Which of the following can be classified as an example of positive work being done on the object in bold?

• A waiter carries a tray of food across the restaurant floor at constant speed.

• A car skids to a stop along a level highway.

• While stretching before a wrestling match, Rashad pushes on a stationary gym wall.

• The team captain lifts a trophy above her head to celebrate victory.

No work is done by gravity on a bowling ball that rolls along a bowling alley because...

• no force acts on the ball.

• little distance is covered by the ball.

• the force on the ball is at right angles to the ball's motion.

• the ball's speed remains constant.

A rightward force of 6.0 N is exerted upon a 2.0-kg object for a distance of 3.0 meters. What is the work done on the object?

• 1.5 J

• 2.0 J

• 6.0 J

• 12.0 J

• 18.0 J

 The work you do when pushing a shopping cart a given distance while applying twice as much force is...

• half as much.

• twice as much.

• four times as much.

• the same amount.

Tags

NGSS.HS-PS3-2

How far does a box move if 50 N of force was applied to do 100 J of work?

• 2 m

• 0.5 m

• 5,000 m

• none of these

If you do work in one-third the usual time, you expend...

• one third as much power.

• the usual power.

• three times the usual power.

• need more information.

How much time is required to produce 300 J of work if 60 W of power is used?

• 0.2 s

• 5 s

• 18,000 s

• need more information

An object that has kinetic energy must be...

• moving

• falling

• at an elevated position

• at rest

• none of the above

Tags

NGSS.HS-PS3-2

The total mechanical energy possessed by an object is equal to ____.

• its kinetic energy

• its potential energy

• its kinetic energy plus potential energy

• its kinetic energy minus potential energy

• its potential energy minus kinetic energy

Tags

NGSS.HS-PS3-2

What factors does the kinetic energy of an object depend upon?

• work and time

• mass and height

• force and distance 

• mass and speed