THE NATURE OF ENERGY

Chapter 5

Section 1

ENERGY Every change that occurs requires energy. Energy is the ability to do work. All moving objects have energy You can tell an object has energy when it:

Changes its environmentChanges itself

Energy can be stored and moved from place to place

FORMS OF ENERGY

Energy exists in many different forms It may look different, but it’s still energy.

Examples: electrical, chemical, radiant, and thermal

HOW IS ALL ENERGY DIVIDED?

PotentialEnergy

Kinetic

Energy

All Energy

Gravitation

PotentialEnergy

ElasticPotentia

lEnergy

ChemicalPotentialEnergy

KINETIC ENERGY Kinetic energy- energy in the form of

motionDepends on mass and speed of an object Increase in either mass or speed = increase

in energyKE =1/2 mv2

Units = kg*m/s The SI unit is called joule (J).

KE = ½ mv2 velocity changes will impact KE more because velocity is squared.

EXAMPLES OF KINETIC ENERGY…

Shooting a rubber band.

Water falling over the fall.

A Yo-Yo in motion.

Releasing the arrow from the bow.

POTENTIAL ENERGY Potential Energy is stored energy.

Stored chemically in fuel, the nucleus of atoms, and in foods.

Or stored because of the work done on it: Stretching a rubber band. Winding a watch. Pulling back on a bow’s arrow. Lifting a brick high in the air.

EXAMPLES OF POTENTIAL ENERGY:Stretching a rubber band.. -Stores energy

Water at the top of a waterfall. -Stores energy

Yo–Yo in held in your hand.. -Stores energy because of position

Drawing a Bow… -Stores energy because of position

ELASTIC POTENTIAL ENERGY

Energy that is stored due to being stretched or compressed is called elastic potential energy.

CHEMICAL POTENTIAL ENERGY Chemical Potential Energy – Energy

stored in chemical bondsGasoline, food, hand warmers

GRAVITATIONAL POTENTIAL ENERGY

Gravitational Potential Energy- Energy stored due to position above the surface of EarthGravitational Potential Energy called "GPE"

is a measure of how far an object can fall.The higher up it is, the further it can fall and the more GPE it has.

GPE depends on the object's mass and height.

GPE = m x h x a(9.8m/s ²)Like all other forms of energy GPE is measured in joules.