WHAT IS ENERGY?
Energy is the ability to do work.
TWO MAIN FORMS OF
Potential Energy is energy at rest.
The amount of potential energy an object has depends on the position of the object.
Example: A car parked at the top of a hill. The car is parked (not moving), but has the potential to move.
Kinetic Energy is energy in motion.
The amount of kinetic energy depends on the speed and mass of an object.
Example: A snowball rolling down a hill. The more snow the snowball accumulates the faster it will roll
down the hill increasing the amount of kinetic energy the snowball has.
DIFFERENT FORMS OF
Mechanical Energy is the sum of potential energy and kinetic energy.
The formula for mechanical energy is P.E. + K.E.= M.E.
Example: A pendulum has a potential energy of 1.5 joules and a kinetic energy of 3.5 joules.
What is the mechanical energy of the pendulum?
P.E. + K.E. = M.E.
1.5 + 3.5 = 5.0 joules
Chemical Energy is a form of potential energy.
Chemical Energy is stored fuel.
Example: Sandra ate a hotdog for lunch. The hotdog is now being used as chemical energy.
Food is fuel for the body.
Thermal Energy is heat.
Thermal Energy is found in every energy conversion.
Thermal Energy can be used through means of conduction, convection, and
Example: The wood burning is producing massive amounts of heat.
Sound energy is vibrations in the air.
Sound energy is sound waves that switch from potential to kinetic energy
Example: Playing the drums in a band. When the drumsticks hit the drum sound waves
Light Energy (Electromagnetic Energy) is waves that can travel anywhere.
Light Energy has energy levels. The lower the energy, the longer the
wavelength. The higher the energy the higher the wavelength.
There are many different forms of light waves.
Example: Light energy used in tanning beds is known as ultraviolet light waves.
Electrical Energy is also known as Electricity.
Electricity is the flow of electrons.
Electricity in our home runs through circuits.
Many homes being built today are built to be “more energy efficient” meaning
they use less electrical energy.
Example: Electrical energy is used for lighting, cooking, heating, and for entertainment in