Exam 4: Work and Energy

An object has kinetic energy of 324 J. If its speed is 9 m/s, what is its mass?

A horsepower is a unit of power equal to 550 ______________.

When the height of an object is doubled, its gravitational potential energy is increased by a factor of ______________.

We define the total mechanical energy of an object as

A mixture of ethanol and gasoline is called

A joule per second (J/s) is a

Which of the following is not a unit of work?

What is bought from an electric company?

Which of the following is not a unit of power?

A stone is dropped from a bridge 15 m above a river. With what speed does the stone hit the water? ​ ​

Work in the amount of 280 J is done in lifting an object a distance of 4.0 m in a time of 7.0 s. a. How much force did it take to lift the object? b. What was the power input?

Power is

Potential-energy values may be

If you lift a 15-N weight vertically 30 m above the ground, you are

A force of 12 N acts on a 2.0-kg object through a parallel distance of 1.5 m. How much work is done on the object?

Which of the following four objects has the greatest kinetic energy?

With a constant braking force, the stopping distance of a car is proportional to ______________.

In pushing an object on a level surface, work is done against ______________.

A negative potential energy may be made positive by changing the ______________ point.

A kilowatt-hour is a unit that measures