(Chapter 4)

 

Energy = the ability to cause change or do work. 

·       Example: whenever you do anything, you got the energy to do it from the food you ate.  When your car moves, it gets the energy from gasoline. 

·       The SI unit for energy is the Joule.  

Kinetic Energy (KE) = energy in the form of motion

·       Examples: running, driving, a ball flying through the air…

·       KE depends on mass and velocity, like momentum

o     More mass, more KE

o     More velocity, more KE

Potential Energy (PE) = stored energy

·       There are many kinds of PE:

o     Elastic PE = energy stored by something that can stretch or compress, like a rubber band or a spring

o     Chemical PE = energy stored in chemical bonds, such as in food, gasoline, or explosives

o     Gravitational PE = energy stored by objects that are above Earth’s surface, such as a book up on a shelf

§       Objects that are higher up or heavier have more gravitational potential energy