Physical Science Chapter 3 Homework

Flashcard maker : Isabella Parker
The quantity that has units kg * m2/s2 is known as a
joule
Coal that is used in a coal-fired power plant is
ground to a face-powder consistency and blown into furnaces.
The solar technology that is today contributing about as much energy as moving water is
biomass
Of the following, which rank of coal has the most desirable burning properties and highest energy content?
bituminous
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
negative.
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?
Student B did twice as much work climbing to the top of the structure.
Roughly, what fraction of our nation’s current energy needs is supplied by coal?
20%
The amount of energy produced by power-generating dams is
decreasing, as more energy is used but new dams are not being built.
Your electric bill for 1500 kilowatt-hours is a charge for the power you have used that month.
False
Which form of energy does not require matter for traveling through space?
radiant
Which one of the following does not have the same units as the others?
momentum
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
160 ft.
When you throw a ball into the air, its kinetic energy
all of these.
Energy sources used today are mostly in what form of energy?
chemical
You do more work on yourself when you run up the stairs than when you walk slowly.
False
Plants convert radiant energy from the Sun into chemical energy by a process called photosynthesis.
True
As we deplete our coal reserves, we can replace this lost source of energy by increasing our output of hydroelectric power.
False
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?
PE=mgh
The increase in potential energy caused by lifting an object can be calculated by multiplying its weight by its change in height.
True
Kinetic energy refers to
energy of motion.
Which one of the following has an appropriate unit?
All of these.
Work is the rate at which you expend energy.
False
The watt (W) is a unit of
power.
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
zero, because the wall is not moving.
Energy is not conserved when a moving object slows to a stop.
False
Nearly all of the energy consumed today is provided by petroleum, coal, hydropower and nuclear sources.
True
Which solar technology makes economic sense for a homeowner?
water heating
When a light bulb is rated at 60 W, it means that
each second, the bulb converts 60 J of electrical energy to heat and light.
The energy an object has because of its position is called potential energy.
True
An object that falls twice as far will be moving twice as fast when it hits the ground.
False

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