EnergyCh. 13pg. 442

Objectives• Describe how energy, work,

and power are related.

• Name and describe the two basic kinds of energy.

What is Matter?

• Anything that has mass and takes up space. Everything has matter.

What is Energy?

• The ability to do work or cause change

• Particle movement = Energy

• The more movement, the more energy, the more heat that is generated.

Work and Energy

• REMEMBER

• Work = Force x distance

• So when work is done on an object some of its energy is transferred to the other object.

Energy and Power

• REMEMBER

• Power = Work / time

• Power is the rate at which energy is transferred = work

Calculate power and energy

• Power = Energy transferred(work)

time

Two kinds of Energy

1. Kinetic Energy

2. Potential EnergyAll types of energy falls under

one of these forms

Kinetic Energy• Any object in motion is

considered to have kinetic energy.

• Kinetic comes from the Greek word kinetos, which means “moving”

Factors that affect kinetic energy

•Friction•Velocity of the object in motion

•Mass of the object

Calculate Kinetic Energy (KE)

• Kinetic Energy (Joule)

• Mass (g or kg)

• Velocity=speed (m/s)• Kinetic Energy = ½ x mass x velocity2

Potential Energy (PE)

• Stored energy that results from the position or shape of the object.

• Objects that have the potential to move/do work.

• ALL objects not moving have PE.• PE is related to an objects height.

Gravitational Potential Energy(GPE)

• This is the energy related to an object’s height.

• The higher the object, the more PE the object has.

• GPE = Weight(N) x Height(m)

Elastic Potential Energy (EPE)

• Stretching or compressing of objects

• Example; rubber band, bow and arrow

Forms of EnergyCh. 13-2

Objectives

• How can you determine an object’s mechanical energy?

• What are some forms of energy associated with the particles that make up an object?

Forms of Energy• Mechanical energy• Thermal energy• Electrical energy• Chemical energy• Nuclear energy• Electromagnetic energy

Mechanical Energy• Energy associated with motion.

• Mechanical Energy = PE + KE

Forms of Energy

• Deal with particles that make up the objects.

• Types of particle motion

Thermal Energy• Heat energy stimulated from the

motion of particles within matter.

• The faster the particles move the more heat is generated

Electrical Energy• The energy of electrical charges,

lightning

Chemical Energy• The potential energy stored in the

chemical bonds that hold chemical compounds together.

• Chemical energy is stored in food we eat and in turn is changed into mechanical energy.

Nuclear Energy• The energy stored in the nucleus of an

atom.• The sun goes through nuclear fusion

constantly combining hydrogen atoms with helium atoms. This results in the light and heat we see.

• Fission is the splitting of an atom creating nuclear bombs.

Electromagnetic Energy• Energy that travels in waves.

• X-rays, microwaves, ultraviolet (UV), infrared radiation, and radio waves.

Energy Transformation and Conservation

• How are different forms of energy related?

• What is a common energy transformation?

• What is the law of conservation of energy?

Energy Transformations• A change from one form of energy

to another form to get work done.

• Ex. Chemical(energy in food) to Mechanical(energy of motion to move your muscles)

Energy Conservation• Law of Conservation of Energy states

that when one form of energy is transformed to another, no energy is

destroyed in the process.

Energy cannot be created nor destroyed it just changes

form.

How can energy be created?

• By destroying matter.

• Ex. If I burn a log to ash. I am destroying matter, but creating many types of energy.

• Chemical

• Thermal

• Light

Questions/Review

1. What is the relationship between different forms of energy?

2. When you turn a toaster on, what happens to the electrical energy?

3. Describe the energy transformations that happen whey you strike a match. List them in order in which they occur.

1. They can be transformed into other forms of energy.

2. Electrical energy is transformed to thermal energy.

3. First, striking the match mechanical energy to thermal energy. Thermal energy causes particles to release into chemical energy. Chemical energy is transformed to thermal and electromagnetic energy.

Energy Sources

• Renewable

• Nonrenewable

Renewable Energy• Are sources that can be replenished in a

short period of time. 1. Water (hydropower)2. Wind3. Solar4. Geothermal (heat from the Earth’s

center)5. Biomass – wood and waste porducts

Hydroelectric Power

Wind Power

Biomass

Geothermal Energy

Solar Power

What role does renewable energy play in the U.S.?

• Over half of renewable energy goes to producing electricity.

Nonrenewable Resources

• Sources of energy not able to be renewed or replenished.

• Fossil Fuels1. Oil and petroleum products (gasoline,

diesel fuel, and propane)2. Natural gas3. Coal4. Uranium (nuclear energy)