Physical Science Chp 3 Energy

heat radiation

Infrared radiation is sometimes called heat radiation because of the association with heating when this type of radiation is absorbed.

Nuclear energy

Is a form of energy often discussed because of its use as an energy source in power plants.

Electrical energy

Is another form of energy from electromagnetic interactions that will be onsidered in detail later.

Geothermal Energy

Is energy from beneath Earth's surface.

Radiant energy pg 73

Is energy that travels through space.

Chemical energy pg 72

Is the form of energy involved in chemical reactions.

Mechanical energy

Is the form of energy of familiar objects and machines.

Hydrogen

Is the lighter and simplest of all the elements, occurring as a diatomic gas that can be used for energy directly in a fuel cell or burned to release heat.

Mechanical work pg 64

Is the product of a force and the distance an object moves as a result of the force.

Increase combinations of kinetic energy, potential energy, and/or temperature.

Isolated occurrences are more the exception than the rule.

Work against any combination of inertia, fundamental, forces, friction, and/or shape.

It is a rare occurrence on Earth that work is against only one type of resistance.

flow of energy

It takes place in your surroundings.

horsepower pg 65-66

James Watt, a workable steam engine, defined horsepower as a power rating of 550 ft-lb/s

gravitational potential energy

This a called gravitational potential energy, since it is a result of gravitational attraction.

Agriculture and industrial heating

This is a technology that simply uses sunlight to dry grains, cure paint, or do anything that can be done with sunlight rather than using traditional energy sources.

Ocean thermal energy conversion (OTEC)

This is an electric generating plant that uses the temperature difference between the surface and the depth of tropical, subtropical, and equatorial ocean water.

Power tower

This is another solar technology designed to generate electricity, by using sunlight to create heat.

Unit of Work

W = Fd

penstocks

Water from a reservoir is conducted through large pipes called penstocks to a powerhouse, where it is directed against turbine blades that turn a shaft on an electric generator.

Increased temperature

Work against friction results in an increase in the temperature.

Increased potential energy

Work against gravity and work against shape result in an increase of potential energy, the energy of position..

Increased kinetic energy

Work against inertia results in an increase of kinetic energy, the energy of motion.

Work was done against various resistances, and energy was increased as a result.

You could say that energy of position, and it, too, has the ability to do work.

working or heating

You could summarize this by stating that either working or heating is always involved any time energy is transformed.

Summary pg 82 Work joule power horsepower energy potential energy energy of position energy of motion kinetic energy against inertia gravity friction shape

combinations of these forms of mechanical, chemical, radiant, electrical, or nuclear converted energy from converters law of conservation of energy fossil fuels Petroleum natural gas peat ranks solar geothermal hydrogen

Key Terms pg 82 chemical energy 72 electrical energy 73 energy 68 fossil fuels 71 geothermal energy 81 horsepower 65 joule 64

kinetic energy 69 law of conservation of energy pg 75 mechanical energy 71 nuclear energy 73 potential energy 68 power 65 radiant energy 73 watt 66 work 63

book

the book did work on the object through the string. W = Fd

potential

the greater he potential for the book to do work.

Energy Forms

various forms, this does not mean that there are different kinds of energy.

Newtons

(N), and distance is measured in meters (m), so the unit of work is W = Fd W = (newton) (meter) 2 = (N)(m)

Joule

1 joule = 1 newton-meter

Energy can be categorized into five forms

1) Mechanical 2) chemical, 3) radiant, 4 electrical, and 5) nuclear

Resources that occur in four broad categories of geothermal energy:

1) dry steam 2) hot water 3) hot, dry rock, and 4) geopressurized resources

Energy Forms

1) mechanical 2) chemical 3) radiant 4) electrical 5) nuclear

nine

A ball with three times the velocity will do nine times as much work as the slower ball.

Work against inertia

A net force that changes the state of motion of an object is working against inertia.

Solar cells

A solar cell is a thin crystal of silicon, gallium, or some polycrystalline compound that generates electricity when exposed to light.

Passive application

In passive applications, energy flows by natural means, without mechanical devices such as motors, pumps, and so forth.

Hydrogen + oxygen + water + 68,300 calories

In addition to the heat produced, the only emission from burning hydrogen is water, as shown in the following equation:

Active application

An active solar application requests a solar collector in which sunlight heats air, water, or some liquid.

Energy Sources Tomorrow pg 80

An alternative source of energy is one that is different from the typical sources used today.

Energy Conversion pg 75

Any form of energy can be converted to another form

Geopressurized resources

Are trapped underground reservoirs of hot water that contain dissolved natural gas.

Biomass

Biomass is any material formed by photosynthesis, including small paints, trees, and crops, and any garbage, crop residue, or animal waste.

oxidation

Chemical energy is released in the chemical reaction known as oxidation.

Conserving Energy pg 79

Conservation is not a way of generating energy, but it is a way of reducing the need for additional energy consumption, and it saves money for the consumer.

energy-form converts

In fact, most technological devices that you use are nothing more than energy-form converters.

Work against gravity

Consider the force from gravitational attraction.

Motion, Position, and Energy pg 68

Energy can be defined as the ability to do work.

Energy Conservation

Energy can be transferred from one object to another, and it can be converted from one form to another form.

Law of conservation of energy:

Energy is never created or destroyed. Energy can be converted from one form to another, but the total energy remains constant.

fission

Energy is release as the nuclei of uranium and plutonium atoms split, or undergo a nuclear reaction called fission and form new elements.

Energy Force pg 63

Force has a special meaning in science that is different from your everyday concept of force.

fossil fuels

Fossil fuels contain the stored radiant energy of organisms that lived million of years ago.

total energy

Hydroelectric plants generate about 3 percent of the nation's total energy consumption at about 2,400 power-generating dams across the nation.

hot, dry rock,

Most geothermal energy occurs as hot, dry rock, which accounts for about 85 percent of the total geothermal resource.

Moving water

Moving water has been used as a source of energy for thousands of years.

Nuclear pg 78

Nuclear power plans use nuclear energy to produce electricity.

Coal

Petroleum, natural gas, and coal are called fossil fuels. Fossil fuels contain the stored radiant energy of organisms that lived million of years ago.

energy due to position

Potential energy is defined as energy due to position, since it is a result of gravitational attraction.

Power per unit of time, power = work ______ time P = W _____ t

Power is measured as work

four

The ball with twice the velocity will do four times as much work as the slower ball.

barrel pg 77

The barrel is an accounting device of 42 U.S. gallons.

potential

The book now has the potential of doing 10 J of additional work on something else; therefore,

fly ash

The coal is ground to a face-powder consistency and blown into furnaces. This greatly increase efficiency but produces fly ask, ash that "flies" up the chimney.

Kinetic Energy pg 69

The energy of motion is known as kinetic energy 1) the work done to put the object in motion or 2) the work the moving object will do in coming to rest

potential energy

The energy that an object has because of its position is called potential energy (PE).

reactor

The fissioning takes place in a large steel vessel called a reactor.

Work against friction

The force that is needed to maintain the motion of an object is working against friction.

Work against shape

The force that is needed to stretch or compress a spring is working against the shape of the spring.

It does not exist

The primary problem with using hydrogen as an energy source is that it does not exist on or under Earth's surface in any but trace amounts!

Power pg 65

The rate at which energy is transformed or the rate at which work is done is called:

change of position

The same results would be obtained in either case since it is the change of position that is important in potential energy.

watt pg 66

The unit j/s, however, has a name. A j/s is called a watt (w)*.

Wind energy

The wind has been used for centuries to move ships, grind grain into flour, and pump water.

Petroleum

The word petroleum is derived from the Greek word petra meaning rock, and the Latin word oleum, meaning oil.

Work

The word work represents another one of those concepts that has a special meaning in science that is different from your everyday concept.

work = force x distance w = Fd

The work done on the object is defined as the product of the applied force and the parallel distance through which the force acts:

ranks

There are several stages, or ranks, in the formation of coal.

Mechanical work defined:

There are two important considerations to remember about this definition; 1) something must move whenever work is done, 2) the movement must be in the same direction as the direction of the force.