Chapter 4, Section 1 Notes The Nature of Energy

Energy – Every change that occurs requires energy Energy – Every change that occurs requires energy. The Nature of Energy – All of the changes that occur around you every day involve the conversion of energy from one form to another.

A. Energy is the ability to cause change A. Energy is the ability to cause change. Therefore, anything that causes change must have energy. There are several different forms of energy, such as electrical, chemical, radiant, and thermal. Like money, energy can change from one form to another.

Kinetic energy – Energy in the form of motion. a. The amount of kinetic energy an object has depends on its mass and its speed. b. Kinetic energy – ½ mass x speed2 (in m/s) c. Joule – The SI unit used to measure energy. d. Apply the kinetic energy equation on page 102.

Potential energy – Energy stored in a motionless object, giving it the potential to cause change. Example: a hanging apple in a tree Elastic potential energy – Energy stored by things that stretch or compress. Examples: a rubber band or spring

Chemical potential energy – Energy stored in chemical bonds between atoms. Examples: eating food or USING gasoline. Gravitational potential energy – Energy stored by things that are above Earth. a. The amount of GPE an object has depends on its mass, the acceleration due to gravity, and its height above ground.

GPE = mass in kilograms x 9.8 m/s2 x height in meters. Apply the GPE formula on page 104.