1. Forms and Transformations
ENERGY
Forms and Transformations

2. What is energy? Energy is the ability to do work or cause change.
It can change the temperature, shape, speed, or direction of an object.

3. How are energy, work, forces and matter related?
Energy is the ability to do work.
Work is done when an object is moved.
An object can only be moved when a force (push or pull) is applied to it.
A force is caused by some form of energy.
Anything that occupies space and has mass is matter.
…And all matter has energy.

4. What are the two basic kinds of energy?
Potential energy is stored energy based on position and / or composition.
Kinetic energy is energy in motion.
As kinetic energy of an object increases, potential energy of the object decreases.

5. What are some additional forms of energy?
Chemical P.E. – stored in chemical bonds between atoms and molecules; released through chemical reaction
Gravitational P.E. – depends on the height of an object
Elastic P.E. – stored in stretched or compressed objects
Nuclear P.E. – stored in the nucleus of atoms; released through fission or fusion

6. More forms of energy…
Electromagnetic K.E. – energy of light and other forms of radiation (radio, UV, X-ray); travels in waves
Sound (K.E.) – energy disturbance that travels through a medium as a wave
Thermal (P.E. and K.E.) – total P.E. and K.E. of the particles in an object; when T.E. increases, object gets warmer
Electrical (P.E. or K.E.) – energy of electric charges, stored or in motion

7. What is an object’s mechanical energy?
Mechanical energy is associated with the position and motion of an object.
M.E. is a combination of an object’s potential energy and kinetic energy.

8. Energy Transfers
Energy can move from one object to another without changing forms. This movement is called an energy transfer.
For example: an electrical outlet transfers electrical energy through the cord to a lamp.

9. Energy Transformations
Most forms of energy can be changed into other forms. This change is called an energy transformation.
- (A toaster transforms electrical energy
to thermal energy)
One of the most common transformations is between potential and kinetic energy.
- (A stretched rubber band (E.P.E.) is
let go (K.E.))

10. How to show energy trans.
We use short-hand to show energy transfers and transformations.
Cause Effect
Object before
Object
after
Energy before
Energy
Identify the OBJECT before and after.
Identify the ENERGY before and after.

11. What is the Law of Conservation of Energy?
Energy cannot be created or destroyed.
When one form of energy is transformed to another, the total amount of energy is the same before and after the process.
During some transformations, energy is “lost” as heat energy from friction and cannot be reused. (Not destroyed).