Deck 3: Energy

Question 1

Work is the rate at which you expend energy.

Answer 1

False

Question 2

When a light bulb is rated at 60 W, it means that

A)the bulb uses 60 J of power when it is lit.
B)current is traveling at 60 m/s through the filament.
C)each second, the bulb converts 60 J of electrical energy to heat and light.
D)the bulb loses 60 W of potential energy each second.

Answer 2

C

Question 3

As we deplete our coal reserves, we can replace this lost source of energy by increasing our output of hydroelectric power.

Answer 3

False

Question 4

Your electric bill for 1500 kilowatt-hours is a charge for the power you have used that month.

Question 5

The amount of energy produced by power-generating dams is

A)increasing, as more of this clean, non-polluting resource is used.
B)increasing, as more renewable resources are used.
C)decreasing, as more energy is used but new dams are not being built.
D)decreasing, as old dams are destroyed for environmental reasons.

Question 6

Energy is not conserved when a moving object slows to a stop.

Question 7

Which one of the following has an appropriate unit?

A)work - joule
B)force - newton
C)power - watt
D)All of the above.

Question 8

Plants convert radiant energy from the Sun into chemical energy by a process called photosynthesis.

Question 9

Coal that is used in a coal-fired power plant is

A)broken into rice-sized granules and transported on belts.
B)ground to a face-powder consistency and blown into furnaces.
C)burned in baseball-sized chunks for a hotter fire.
D)transported and burned in all sizes of coal chunks.

Question 10

The quantity that has units is known as a

A)joule.
B)newton.
C)horsepower.
D)watt.

Question 11

Which one of the following does not have the same units as the others?

A)kinetic energy
B)momentum
C)potential energy
D)work

Question 12

A car traveling 20 mph can stop in about 40 ft.If the same car were traveling twice as fast, its stopping distance would be roughly

A)40 ft.
B)60 ft.
C)80 ft.
D)160 ft.

Question 13

When you throw a ball into the air, its kinetic energy

A)equals .
B)equals the work you did on the ball.
C)is converted to potential energy as it goes higher.
D)All of the above.

Question 14

The watt (W) is a unit of

A)work.
B)electrical energy.
C)power.
D)force.

Question 15

The energy an object has because of its position is called potential energy.

Question 16

You do more work on yourself when you run up the stairs than when you walk slowly.

Question 17

Nearly all of the energy consumed today is provided by petroleum, coal, hydropower and nuclear sources.

Question 18

The increase in potential energy caused by lifting an object can be calculated by multiplying its weight by its change in height.

Question 19

Kinetic energy refers to

A)energy of motion.
B)energy of position.
C)energy stored in fossil fuels.
D)electrical energy.

Question 20

An object that falls twice as far will be moving twice as fast when it hits the ground.

Question 21

You can find the kinetic energy of a book of a certain mass just before it hits the floor after falling a certain distance by using which equation?

A)W = Fd
B)K.E.= ½ mv²
C)P.E.= mgh
D)None of the above.

Question 22

Energy sources used today are mostly in what form of energy?

A)electrical
B)chemical
C)radiant
D)nuclear

Question 23

The solar technology that is today contributing about as much energy as moving water is

A)solar cells.
B)OTEC.
C)power tower.
D)biomass.

Question 24

Which solar technology makes economic sense for a homeowner?

A)solar cells
B)water heating
C)power tower
D)biomass

Question 25

Two students stand poised to leap off a high dive structure into the swimming pool below.Student B is twice as massive as student A.Which of the following is true?

A)Student B will reach the ground sooner than student A.
B)Both students have the same gravitational potential energy.
C)Both students will have the same kinetic energy just before impact.
D)Student B did twice as much work climbing to the top of the structure.

Question 26

Of the following, which rank of coal has the most desirable burning properties and highest energy content?

A)peat
B)lignite
C)subbituminous
D)bituminous

Question 27

Which form of energy does not require matter for traveling through space?

A)electrical
B)chemical
C)radiant
D)mechanical

Question 28

Roughly, what fraction of our nation's current energy needs is supplied by coal?

A)10%
B)20%
C)40%
D)80%

Question 29

While exploring an ancient Mayan tomb, you discover that the walls are closing in on you.By exerting 400 N of force, you are able to keep the wall from coming closer.The work you are doing on the wall is

A)400 J.
B)3920 J.
C)unknown, because the mass of the wall is not given.
D)zero, because the wall is not moving.

Question 30

The potential energy of a ball on the ground is zero.If the ball is now in the bottom of a hole, its potential energy is

A)non existent.
B)the same as it was on the surface.
C)negative.
D)zero.