Energy Mr. Skirbst Physical Science Topic 07

What is energy?

-It is the ability to do work or cause change (remember: work = force x distance) Unit of energy = Joule

5 FORMS of Energy

1.Mechanical - “matter in motion” - (ex. ball, bike, run, blood)

5 FORMS of Energy 2.Heat - “atomic motion” - (ex. melting, evaporation)

5 FORMS of Energy 3.Chemical - “atomic bonding” - (ex. burning, reactions)

5 FORMS of Energy 4.Electromagnetic - “moving electrons” - (ex. electricity, lights, motors)

5 FORMS of Energy 5.Nuclear - “fusion / fission” - (ex. stars, atomic bomb)

2 STATES of Energy

1.Kinetic (Greek – “kinetikos” motion) - energy of motion

2 STATES of Energy * depends upon mass & velocity K.E. = (mv 2 ) / 2 m = mass; v = velocity

2 STATES of Energy 2.Potential - energy of position * stored energy (ex. food, fuel, suspended objects)

2 STATES of Energy “The bigger they are, the harder they fall” P.E. = mgh m = mass; g = gravity; h = height

Energy Conversions Energy can be transferred from one object to another & from one form to another

Example Problems m = 2 kg;v = 2 m/sec