Chapter 3: Motion
The Greek word petra meaning ______ and the Latin world oleum for ______ were combined to form the world petroleum.
rock; oil
A simple machine allows a small force to be applied over a large distance (effort distance) so that a large force is working over a _____ distance (resistance distance).
small
Technologies that directly or indirectly use sunlight as an alternative energy source are the basis of _____ energy.
solar
If work is done on an object, the object has more energy than it did before. This energy can come from increases in kinetic energy, potential energy, and/or _____.
temperature
Coal forms from _____
the accumulation of plant matter as sediment in swamps of swamp like environments.
When energy is _____, work or heating occurs.
transformed
A mechanical advantage is the advantage gained by ______
using a machine
Biodiesel, used in diesel engines, is a _____
vegetable-based oil
What variable has the greatest effect on the kinetic energy of an object?
velocity
The energy-source mix in the United States has changed over time. What represents the dominant source of energy from past to present?
wood to coal to petroleum
A kilowatt-hour is a unit of _____
work
What is the formula that defines work?
work = force x distance; w =Fd
The wholesale cost of a "barrel of oil" is often reported by news organizations. How many U.S. gallons are in a "barrel of oil"?
42 gallons
mechanical energy (example)
A motorcycle moving on a highway.
active application
A solar collector in which sunlight heats air, water, or some liquid that is pumped in pipes to generate electricity.
hot, dry rock
Accounts for 85% of the total geothermal resource; normally occurs near former volcanic activity.
How can energy be transformed?
Energy can be transferred back and forth between kinetic and potential energy.
nuclear energy (example)
Energy released from the nucleus of an atom.
True of False: Energy cannot be converted from kinetic to potential energy.
False
What must change for an object so it can be said that a force has been applied to it?
Its motion.
What are the formulas that can be used to determine the mechanical advantage (MA)?
MA = effort distance/resistance distance; MA = resistance force/effort force
hot water
Makes up most of the recoverable geothermal resources; results from convection patterns in groundwater.
What is true regarding matter supplying energy?
Matter can be moving or at rest.
If force is applied to an object but that object does not move, has work been done on it?
No; an object must move if work is done on it.
If an object moves at right angles only to the force applied to it, has work been done on the object by the force?
No; the direction of motion for work must be parallel to the direction of the force.
dry steam
Occurs rarely and most known examples are in national parks in the United States.
radiant energy (example)
The heat energy coming off of warm rocks at night.
chemical energy (example)
The oxidation of food units in the body.
geopressurized resources
Underground collections of hot water that contain dissolved natural gas.
solar cell
Uses a polycrystalline compound that generates electricity when exposed to light.
passive application
Uses energy flow by natural means without the use of mechanical devices.
power tower
Uses thousands of small mirrors focused on a boulder filled with molten salt to generate steam.
Work done against a resistance results in ____ energy.
an increase in
Alternative energy sources are those that _____
are not in widespread use today
Natural gas forms in much the same way that petroleum does. The major difference is natural gas forms ____
at higher temperatures
In the United States, most utility companies generate the majority of the electricity by ____
burning coal
The combustion of fuels is a form of _____ energy. It is the most widely used source of energy in the United States.
chemical
The most widely used sources of energy in the United States are from _____
chemical sources
Hydrogen is not a widely used fuel source because ______
concentrating it for use requires an energy input equal to or greater than what you get back out.
Fossil fuels ____
contain the stored radiant energy of organisms that lived millions of years ago
The mechanical advantage can be determined by _____ resistance force by the effort force or the effort distance by the resistance distance.
dividing
In what ways can kinetic energy be measured? It can be measured in terms of the work ______
done to place an object in motion; the object will do when coming to rest
The most abundant type of geothermal energy is hot ____ rock. It accounts of about 85% of the total geothermal energy. However, hot _____ systems make up most of the recoverable geothermal sources.
dry; water
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 work is known as _____
energy
What are the parts of the law of conservation of energy?
energy can be converted from one form to another but the total energy remain constant; energy is never created or destroyed
The national energy intensity in the United States (energy use per unit of GDP) fell about 43% between 1973 and 2002. The majority of the decrease can be attributed to ____
energy efficiency improvements
Any form of energy can be converted into another form of energy. This is how most technological devices work: they are ______
energy-form converters
If friction is ignored, then the work put into a simple machine is ______ the work you get out of it.
equal to
Nuclear power produces electricity by using the energy released during _____, which in turns heats water to create steam. The team is used to run a turbine.
fission
Work is the application of a _____ to an object and the parallel ______ the object moves.
force; distance
In determining the potential energy of an object, the zero reference point is the point ______
from which a change of position is measured.
The energy stored beneath the Earth's surface due to the higher internal temperatures of the Earth is known as _____ energy.
geothermal
Poor insulation, hot engines, and hot lightbulbs all point to ____ waste as the number one cause of energy loss to the environment.
heat
One _____ is defined as a power rating of 550 ft-lb/s.
horsepower
What are some characteristics of the energy source of moving water?
it is a renewable source of energy; it is limited, in part, by geography
What are the benefits of using hydrogen as a fuel source?
it produces no pollutants; water is a by-product; it releases lots of energy when combined with oxygen
A _____ is a measure of how much work an object can do based on its position; it is a measure of potential energy.
joule
A watt is defined as one ____ per second.
joule
The energy due to motion is known as _____ energy.
kinetic
The supply of petroleum and natural gas is _____
limited
In a vacuum where air resistance is zero, which variable below has no effect on the final falling velocity of an object?
mass
Kinetic energy can be determined by taking one-half the _____ of an object multiplied by the ______ squared.
mass; velocity
The force or distance advantage you gain by using a machine is called the ______ advantage.
mechanical
In the metric system, the equation for determining gravitational potential energy is PE = ____
mgh
What are some examples of radiant energy?
microwaves used in a microwave oven; visible light from the Sun; infrared radiation from a fire
The unit of work is a joule. A joule is defined as one ______.
newton-meter
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 ____ and the unit for distance is a ____
newton; meter
Energy due to an object's position is known as ______ energy.
potential
Work divided by time equals _____
power
