Law of Conservation of Energy Energy cannot be created or destroyed. Most forms of energy can be transformed into other forms. Usually changes into thermal energy due to friction.

Energy Conversion Energy can be changed from one form to another. –This is called an energy conversion.

Kinetic-Potential Energy Conversions As a basketball player throws the ball into the air, various energy conversions take place.

Kinetic-Potential Energy Conversions A B C D E Most potential energy Least kinetic energy Least potential energy Most kinetic energy Mechanical energy at each point is the SAME!!!! As potential energy rises – kinetic energy falls. As kinetic energy rises – potential energy falls.

Energy conversions All forms of energy can be converted into other forms. –The sun’s energy through solar cells can be converted directly into electricity. –Green plants convert the sun’s energy (electromagnetic) into starches and sugars (chemical energy). –Our hands convert kinetic energy to thermal energy when we rub them together.

Albert Einstein Theory of Relativity Energy can sometimes be created by destroying matter (nuclear reaction).

Single Transformations When 1 form of energy needs to be transformed into another to get work done. Ex: Toaster Electrical Energy Thermal Energy

Multiple Transformations When a series of energy transformations is needed to do work. Ex: Listening to a radio Electrical Energy Mechanical energy (sound waves) Kinetic energy (eardrum vibrating) Chemical and electrical energy (nerve cells of ear and brain)

Other examples of energy transformations Rubbing your hands together Mechanical energy Thermal energy Hydroelectric plant Mechanical energy (of moving water) Electrical energy

Other energy conversions –In an electric motor, electromagnetic energy is converted to mechanical energy. –In a battery, chemical energy is converted into electromagnetic energy. –The mechanical energy of a waterfall is converted to electrical energy in a generator.

Energy Conversions In an automobile engine, fuel is burned to convert chemical energy into heat energy. The heat energy is then changed into mechanical energy.