Physical Science Chapter3

According to the definition of mechanical work, pushing on a rock accomplishes no work unless there is

Movement in the same direction as the direction of the force

The metric unit of a joule is a unit

any of the above

a N x m/s is a unit of

power

A kilowatt-hour is a unit of

work

A power rating of 550 ft x lb per s is known as a

horsepower

A power rating of 1 joule per s is known as a 

watt

According to PE=mgh, gravitational potential energy is the same thing as

work against a vertical change of position

Two cars have the same mass, but one is moving three times as fast as the other. How much more work will be needed to stop the faster car?

nine times as much

Kinetic energy can be measured in terms of

both a and b

Potential energy and kinetic energy are created when work is done to change a position(PE) or a state of motion (KE). Ignoring friction, how does the amount of work done to make the change compare to the amount of PE or KE created?

both are the same

Many forms of energy in use today can be traced back to

the sun

In all of our energy uses, we find that

the total amount of energy is constant in all situations

Any form of energy can be converted to another, but energy used on Earth usually ends up in what form?

Radiant

Radiant energy can be converted to electrical energy using

Solar Cells

The “barrel of oil” mentioned in discussions about petroleum is

42 U.S. gallons

The amount of energy generated by hydroelectric plants in the United States as a percentage of the total electrical energy is

decreasing because new dams are not being constructed

Fossil fuels provide what percent of the total energy consumed in the United States today?

86 percent

Alternative sources of energy include

all of the above

A renewable energy source is

biomass

The potential energy of a box on a shelf, relative to the floor, is a measure of

all of the above

A rock on the ground is considered to have zero potential energy. In the bottom of a well, the rock would be considered to have 

zero potential energy but would require work to bring it back to ground level

Which quantity has the greatest influence on the amount of kinetic energy that a large truck has while moving down the highway?

Velocity

Electrical energy can be converted to

any of the above

Most all energy comes to and leaves Earth in the form of

radiant energy

A spring-loaded paper clamp exerts a force of 2N on 10 sheets of paper that are held tightly together. Is the clamp doing work as it holds the papers together?

No

The force exerted when doing work by lifting a book bag against gravity is measured in units of

N

The work accomplished by lifting an object against gravity is measured in units of

J

An iron cannonball and a bowling ball are dropped at the same time from the top of a building. At the instant before the balls hit the sidewalk, the heavier cannonball has a greater

Kinetic Energy

Two students are poised to dive off equal-height diving towers into a swimming pool below. Student B is twice as massive as Student A. Which of the following is true?

Student B did twice as much work climbing the tower

A car is moving straight down a highway. What factor has the greatest influence on how much work must be done on the car to bring it to a complete stop?

How fast is it moving

Two identical cars are moving straight down a highway under identical conditions, except car B is moving three times as fast as car A. How much more work is needed to stop car B?

nine times as much

When you do work on something, you give it energy

every time

Which of the following is not the use of a solar energy technology?

Water from a geothermal spring

Today, the basic problem with using solar cells as a major source of electricity is

Manufacturing cost

The solar technology that makes more economic sense today than the other applications is

Water heating

Petroleum is believed to have formed over time from buried

organic sediments