Physical Science Ch.3
True or False: Energy is not conserved when a moving object slows to a stop.
False
True or False: Energy cannot be converted from kinetic to potential energy.
false
What is the unit of work?
A newton-meter (Joule)
The result of work done against inertia is a change in... A. kinetic energy B. potential energy C. temperature D. weight
A. kinetic energy
A watt is defined as one ______ per second. A. newton B. meter C. horsepower D. joule
D. joule
True or False: You do more work on yourself against gravity when you run up the stairs than when you walk slowly.
False
Can two objects with different speed have the same kinetic energy?
Yes
The distance over which a force is applied when using a lever is called the ______________ distance, and the _____________ distance is the distance moved by the object on which the force is applied.
effort; resistance
The force applied by using a machine is called the _____________ force, and the force the machine is working against is called the ____________ force.
effort; resistance
The ability to do work is known as _____________.
energy
When work is done against a resistance, a(n) _____________ change takes place.
energy
Coal, petroleum, and natural gas are examples of _____________ fuels. They contain the stored radiant energy from organisms that lived millions of years ago.
fossil
The work input to a simple machine is equal to the output as long as _________ is ignored.
friction
One ________________ is defined as a power rating of 550 ft-lb/s.
horsepower
Potential energy is measured in the units of _____________ in the metric system.
joule
The _____________-hour is a unit of work associated with electricity.
kilowatt
Work is the product of the distance an object moves and the force that caused the motion. In the metric system, the unit for the force is a(n) _____________ and the unit for distance is a(n) ______________.
newton; meter
The splitting (fission) of the nucleus of an atom results in the release of energy. This energy provides the raw source of energy in __________ power plants.
nuclear
True or False: Our supply of fossil fuels, such as petroleum and natural gas, is effectively unlimited as technology develops to extract more of it.
false
Work is the application of a(n) ______________ to an object and the ______________ the object moves in the same direction.
force; distance
What is the highest rank in the formation of coal? A. Anthracite B. Subbituminous C. Bituminous D. Lignite E. Peat
A. Anthracite
In a vacuum where air resistance is zero, which variable below has no effect on the final falling velocity of an object? A. Mass B. Gravity C. Height
A. Mass
If force is applied to an object but that object does not move, has work been done on it? A. No; an object must move if work is done on it. B. Yes; although the object did not move, heat was transferred to it. C. Yes; an object does not need to move for work to be done on it.
A. No; an object must move if work is done on it.
The lowest energy electromagnetic waves are _______________ waves, and the highest energy are ____________ rays.
radio; gamma
Technologies that directly or indirectly use sunlight as an alternative energy source are the basis of _______________ energy.
solar
A(n) ______ is an interaction that will change the motion of an object. A. force B. newton C. temperature change D. acceleration
temperature change
A student lifts a 25kg bag of dog food to a height of 3.0 m above the floor in 5.0 s. The power output of the student is... A. 0.20 hp B. 147 hp C. 0.98 hp D. 735 hp
A. 0.20 hp
A student lifts a 25kg bag of dog food to a height of 3.0 m above the floor in 5.0s. The power output of the student (in horsepower) is... A. 0.20 hp B. 147 hp C. 0.98 hp D. 735 hp
A. 0.20 hp
If an object moves at right angles only to the force applied to it, has work been done on the object by the force? A. Yes; if the object is in motion, then the force has performed work. B. No; the direction of motion for work must be parallel to the direction of the force. C. No; the direction of motion can be in any direction other than right angles to the force.
A. Yes; if the object is in motion, then the force has performed work.
Work done against a resistance results in ______ energy. A. an increase in B. the creation of C. a decrease in
A. an increase in
Alternative energy sources are those that ______. A. are not in widespread use today B. are on the cutting edge of technology C. are in common use today
A. are not in widespread use today
Why is solar energy becoming more common for household electricity use? A. becoming less expensive B. chemical storage batteries are dangerous C. solar cells are smaller today than in the past D. becoming more expensive
A. becoming less expensive
The national energy intensity in the United States (energy use per unit of GDP) fell about 50 percent between 1973 and 2012. The majority of the decrease can be attributed to ______. A. energy efficiency improvements B. the increased use of alternative energy sources C. the rise of nuclear power
A. energy efficiency improvements
Kinetic energy refers to A. energy of motion B. energy of position C. energy stored in fossil fuels D. electrical energy
A. energy of motion
If working or heating is being done on an object, you can be sure that ______. A. energy transfer is taking place B. some matter is being converted to energy C. energy is being lost
A. energy transfer is taking place
Any form of energy can be converted into another form of energy. This is how most technological devices work; they are ______. A. energy-form converters B. energy creators C. energy-matter converters D. energy-form conservators
A. energy-form converters
The force or distance advantage you gain by using a machine is called the ______ advantage. A. mechanical B. force C. power D. technical
A. mechanical
The Greek word for rock and the Latin word for oil are combined to create our modern English word(s) ______. A. petroleum B. fossil fuel C. gasoline
A. petroleum
Coal forms from ______. A. the accumulation of plant matter as sediment in swamps or swamplike environments B. the accumulation of microorganisms on the shelf of a shallow sea C. the application of heat and pressure to existing oil deposits
A. the accumulation of plant matter as sediment in swamps or swamplike environments
Which form of energy does NOT require matter for traveling through space? A. electrical B. chemical C. radiant D. mechanical
C. radiant
When energy is ______, work or heating occurs. A. created B. destroyed C. transformed
C. transformed
A 10 kg book bag is dropped from a height of 2.0 m. The speed of the book just before it hits the floor is.... A. 0 m/s B. 6.3 m/s C. 9.8 m/s D. 49 m/s
B. 6.3 m/s
Roughly, what fraction of our nation's electrical energy needs in total is supplied by coal? A. 10 percent B. 15 percent C. 60 percent D. 80 percent
B. 15 percent
Which of the following is the primary source of energy in the United States today? A. Solar B. Petroleum C. Coal D. Nuclear
B. Petroleum
What is the difference between the effort force and the resistance force? A. The only difference is in the sign of the force. Effort force is positive, and resistance force is negative. B. The effort force is the force applied, and the resistance force is the force that is working against the applied force. C. The effort force is force applied by the person, and the resistance force is the force lost in the machine as a result of friction. D. The resistance force is the applied force plus the force of gravity in a direction parallel to the applied force.
B. The effort force is the force applied, and the resistance force is the force that is working against the applied force.
What is the difference between the effort force and the resistance force? A. The resistance force is the applied force plus the force of gravity in a direction parallel to the applied force. B. The effort force is the force applied, and the resistance force is the force that is working against the applied force. C. The only difference is in the sign of the force. Effort force is positive, and resistance force is negative. D. The effort force is force applied by the person, and the resistance force is the force lost in the machine as a result of friction.
B. The effort force is the force applied, and the resistance force is the force that is working against the applied force.
Which of the following are NOT categorized as a form of energy? A. Chemical B. Weight C. Nuclear D. Electrical E. Radiant
B. Weight
Work has a special meaning in science. Which of the following statements describes the scientific meaning of work? A. Work involves only an applied force. B. Work involves an applied force that moves an object through a parallel distance. C. Work is done even if there is no motion due to the applied force. D. Work is done even if the object moves perpendicular to the applied force.
B. Work involves an applied force that moves an object through a parallel distance.
The zero reference point for potential energy is ______. A. fixed B. arbitrary C. positive D. negative
B. arbitrary
Solar energy is the energy produced directly or indirectly ______. A. by the rotation of pulsars B. by utilizing sunlight as an alternative energy source C. during the supernova stage of a star's evolution D. by harvesting energy in the same manner in which the Sun produces energy
B. by utilizing sunlight as an alternative energy source
How much work is required to stop a 1000 kg car moving with a speed of 30 km/hr? A. 70,000 J B. 450,000 J C. 5,000 J D. 35,000 J
D. 35,000 J
Energy sources used today are mostly in what form of energy? A. electrical B. chemical C. radiant D. nuclea
B. chemical
The mechanical advantage can be determined by _____ resistance force by(from) the effort force or the effort distance by(from) the resistance distance. A. squaring B. dividing C. subtracting D. multiplying
B. dividing
The law of conservation of energy states that ______. A. energy is only created in the reactions of stars and destroyed in black holes with the universal amount of energy holding constant B. energy is never created or destroyed. However, it can be converted between different forms of energy with the total remaining constant C. energy can be both created and destroyed as shown by E = mc2
B. energy is never created or destroyed. However, it can be converted between different forms of energy with the total remaining constant
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
B. ground to a face-powder consistency and blown into furnaces
Kinetic Energy is a form of energy that... A. is independent of mass B. involves the motion of an object C. can be either positive or negative D. has no ability to do work
B. involves the motion of an object
Kinetic energy is a form of energy that... A. is independent of mass B. involves the motion of an object C. can be either positive or negative D. has no ability to do work.
B. involves the motion of an object
Which one of the following does NOT use the same units as the others? A. kinetic energy B. momentum C. potential energy D. work
B. momentum
The quantity that has units (kg x m/s²) is known as a... A. joule B. newton C. horsepower D. watt
B. newton
Most of the coal mined today is... A. used to heat homes and businesses B. used by utilities to generate electricity C. used to produce gasoline for automobiles D. not considered a fossil fuel
B. used by utilities to generate electricity
A mechanical advantage is the advantage gained by ______. A. applying a greater force B. using a machine C. decreasing the distance over which the object moves
B. using a machine
A student pushes a cart filled with books up a ramp, a distance of 8.0m, the to library. The student applies a force parallel to the ramp of 300 N to the cart. The work the student does is? A. 37 Nm B. 0.27 N/m C. 2.4 x 10³ Nm D. 2.4 x 10³ N/m
C. 2.4 x 10³ Nm
A 75 kg student is rock climbing. He climbs a vertical wall with a height of 50 m. The change in his gravitational potential energy is... A. 3750 J B. 15 J C. 3.68 x 10⁴ J D. 1.50 x 10⁴ J
C. 3.68 x 10⁴ J
In what form do we use coal in the United States to generate electricity? A. Large lumps B. Coal slush C. Ground-up coal
C. Ground-up coal
Mechanical energy is defined as the sum of the kinetic and potential energies of an object. For a simple pendulum, where friction is ignored, compare the mechanical energy at the top of the arc to that at the bottom of the arc. A. Mechanical energy is greater at the bottom. B. Mechanical energy is greater at the top. C. Mechanical energy does not change. D. The answer depends on how high the pendulum swings.
C. Mechanical energy does not change
Two students, of equal weight, race up 5 flights of stairs. The first student arrives at the top in half the time of the other student. Compare the work done by each student. A. The first student does twice the work. B. The second student does twice the work. C. They each do the same amount of positive work. D. They each do no work.
C. They each do the same amount of positive work.
The most widely used sources of energy in the United States are from ______. A. nuclear sources B. hydropower sources C. chemical sources
C. chemical sources
Hydrogen is not a widely used fuel source because ______. A. the resulting pollutants are too hazardous and very expensive to contain B. there is too great of a risk of a nuclear explosion C. concentrating it for use requires an energy input equal to or greater than what you get back out.
C. concentrating it for use requires an energy input equal to or greater than what you get back out.
Fossil fuels ______. A. contain concentrated amounts of radioactive material that provide a power source upon decay B. are petroleum and gas deposits that contain an abundance of large, recognizable fossils C. contain the stored radiant energy of organisms that lived millions of years ago D. are those fossilized bones that contain large amounts of tar
C. contain the stored radiant energy of organisms that lived millions of years ago
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
C. decreasing, as more energy is used but new dams are not being built
If friction is ignored, then the work put into a simple machine is ______ the work you get out of it. A. less than B. greater than C. equal to
C. equal to
Nuclear power produces electricity by using the energy released during _______, which in turns heats water to create steam. The steam is used to run a turbine. A. fusion B. combustion C. fission D. oxidation
C. fission
In determining the potential energy of an object, the zero reference point is the point ______. A. at which the object is before it moves B. at which an object will come to rest due to gravity C. from which a change of position is measured
C. from which a change of position is measured
As long as the rain falls, ______ is a renewable form of energy, limited in large part by geography. A. kinetic rain B. ice expansion C. hydropower D. wind power
C. hydropower
The law of Conservation of Energy of an isolated system A. states energy can be created B. states energy can be destroyed C. means that the total energy is constant because energy cannot be created or destroyed D. is considered a pseudoscience by the current scientific community
C. means that the total energy is constant because energy cannot be created or destroyed
The potential energy of a ball on the ground is zero. If the ball is then moved to the bottom of a hole, its potential energy is... A. non-existent B. same as it was on the surgace C. negative D. zero
C. negative
Petroleum and natural gas form from heat and pressure over time being applied to ______. A. carbon-rich magma B. inorganic iron minerals C. organic-rich sediments D. the bones of dinosaurs
C. organic-rich sediments
Potential energy is the energy due to ______. A. nuclear force B. chemical bonds C. position D. motion
C. position
The watt (W) is a unit of A. work B. electrical energy C. power D. force
C. power
The conservation of energy is important because we lose most of the potential energy in fuel as ______. A. kinetic energy B. gamma rays C. waste heat D. visible light
C. waste heat
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. unknown, because the mass of the wall is not given C. zero, because the wall is not moving D. 3920 J
C. zero, because the wall is not moving
Two students stand poised to leap off a high dive structure into the swimming pool below. Pat is twice as massive as Chris. Which of the following is true? A. Pat will reach the ground sooner than Chris. B. Both students have the same gravitational potential energy C. Both students will have the same kinetic energy just before impact D. Pat did twice as much work climbing to the top of the structure
D. Pat did twice as much work climbing to the top of the structure.
Horsepower is defined as ______. A. power applied over the distance of an English horserace track B. the mechanical advantage gained by using a typical horse C. the mass of a horse divided by the time it takes the horse to run 100 meters D. a specific amount of power (550 ft-lb/s)
D. a specific amount of power (550 ft-lb/s)
When you throw a ball into the air, its kinetic energy... A. equals (1/2mv²) B. equals the work you did on the ball C. is converted to potential energy as it goes higher D. All of the answers are correct
D. all of the answers are correct
Which of the following has an appropriate unit? A. work - joule B. force - newton C. power - watt D. all of the answers are correct
D. all of the answers are correct
Geothermal energy is the energy stored ______. A. in the rotation forces between two astronomical bodies B. in rocks placed in the heating units of steam generators C. in the chemical bonds of rocks like granite and basalt D. beneath the surface of Earth due to high internal temperatures
D. beneath the surface of Earth due to high internal temperatures
Of the following, which coal type has the most desirable burning properties AND the highest energy content? A. peat B. lignite C. subbituminous D. bituminous
D. bituminous
Electrical energy can be converted to mechanical energy in a(n)... A. flashlight B. Solar cell C. battery D. engine
D. engine
You can find the potential energy of a book of a known mass just before it hits the floor after falling a known distance by using which equation? A. W = Fd B. K.E. = ½mv² C. P.E. = mgh D. none of the answers are correct.
D. none of the answers are correct
A simple machine aids in getting work done by allowing a ______. A. small force to be applied over a short distance to get a large force working over a large distance B. large force to be applied over a short distance to get a small force working over a large distance C. large force to be applied over a large distance to get a small force working over a small distance D. small force to be applied over a large distance to get a large force working over a smaller distance
D. small force to be applied over a large distance to get a large force working over a smaller distance
A kilowatt-hour is a unit of ______. A. force B. time C. power D. work
D. work
True or False: Plants convert energy from the Sun into chemical energy by a process called photosynthesis.
True
True or False: The energy an object has because of its position is called potential energy.
True
True or False: The increase in potential energy caused by lifting an object can be calculated by multiplying its weight by its change in height.
True
Can two objects with different masses have the same kinetic energy?
Yes
Sources of energy that are not in common use today, although they may be well-known, are known as ____________.
alternative
Increasing the _________________ of an object will increase its kinetic energy but not as much as increasing the _______________ of an object, which quadruples the kinetic energy.
mass; velocity
A force is a result of an interaction that is capable of changing the state of _________________ of an object.
motion
One joule (newton-meter) per second is defined as a(n) ___________.
watt