Forms of Energy

What is Matter?Matter is defined as anything that has mass

and occupies spaceAnything you can hold or touch is matterExamples: Books, desks, phones, and so is air,

why air?

Things that are not matter: Light, sound, and electricity

These things are not matter because they have no mass or volume

EnergyEnergy is the ability to change or move

matter

If I were to move a desk, it would require energy

Our bodies require energy to function, we obtain this energy from food

Without energy, living organisms would not survive

Forms of Potential EnergyGravitational Potential EnergyElastic Potential EnergyChemical EnergyNuclear Energy

Gravitational Potential EnergyThe energy that results from its position

above the groundAny system of two or more objects separated

by a distance contains gravitational potential energy

This results from the gravitational attraction between the objects

Elastic Potential EnergyThe energy stored in any type of stretched or

compressed elastic materialExamples include a clock spring, bungee

cord, and rubber band What would happen if I had a rubber band

stretched out and then released it?What happens when a compressed spring is

released?

Chemical EnergyThe energy stored within atoms and

molecules that can be released when a substance reacts

Lets look at an example……

Nuclear EnergyEnergy that comes from the splitting of an

atom, or fusing two atoms togetherThis is an energy stored by the forces holding

subatomic particles together in the nuclei of atoms

Lets imagine a water balloon……

Forms of Kinetic EnergyRadiant EnergyThermal EnergySoundElectrical Energy

Radiant EnergyAKA light energy or electromagnetic energyThis is electromagnetic energy that travels in

transverse waves An example of this is solar power

Thermal EnergyThis is energy that comes from heat and the

vibration of atoms and moleculesExamples include geysers and coal burningAnother example is boiling water

• As the water heats up the molecules began to vibrate and have an increase in velocity. In return this cause the water to heat up

SoundSound is the movement of energy through

substances in longitudinal wavesExamples include echoes and music

Electrical EnergyThis is another term for electricityOur homes are powered by electricityThis results from the flow of charged

particles through wires or other conducting materials

Mechanical EnergyMechanical Energy is defined as:

The sum of the potential and kinetic energy in a system

Ex. When an apple hangs from a tree it has potential energy. As it falls it has both potential and kinetic energy. The sum of both the potential and kinetic energy is called the mechanical energy.

Transformation of EnergyWhen the energy in a system changes from

one form to another (like from potential to kinetic) this is known as transformation of energy

ExampleDuring a roller coaster ride energy changes

many times. At the top of the hill the roller coaster has a lot of potential energy (stored energy).

After this, energy goes through a series of transformations, turning from potential to kinetic energy and back to potential.

The Law of Conservation of EnergySimply put:

Energy cannot be created or destroyed

Energy does not just appearEnergy cannot be created from nothingIt must be due to energy that enters the system

from an external sourceEnergy does not just disappear

It can change forms, but not disappear

Example of Energy Entering a SystemImagine a girl jumping on a trampoline. Say

she bounces 0.5m on the first bounce, and then 1.0m on the second bounce.

Because she is higher after the second bounce, she has more potential energy

The total energy increased, but was due to an external force (the girl pushing with her legs)

Example of Energy not disapperingWhat happens when we bounce a ball?As it bounces, it begins to bounce lower and

lowerThis means after every bounce it has a

decrease in potential and kinetic energy

This energy doesn’t disappear

BUT WHERE DOES IT GO??

Where Does It Go??If all of the kinetic energy of the ball

transformed back into kinetic energy after it bounced, what would happen?

The ball would continue to bounce at the same height

Obviously this isn’t what happens, so where did the energy go?

Where Does It GoWhen the ball hits the ground, some of the

kinetic energy compresses the air around the ball, making a sound

Some of the kinetic energy makes the ball, air, and ground hotter

Because these other forms of energy are not due to motion or position, they are considered nonmechanical energy