Changing Forms of Energy Chapter 14

Energy Energy- the ability to do work or cause a change It can change an objects motion, color, shape, temperature, or other qualities It cannot be created or destroyed, but can be transferred to other objects

Examples of Energy Transfer A lamp changes electrical energy into light energy Gasoline releases a chemical energy that moves a car Other kinds of energy: Sound, light, electricity, magnetism, chemical, nuclear, mechanical, thermal

Kinetic and Potential Energy Kinetic: Energy due to motion Potential: Energy that is not causing any changes now, but could cause changes in the future Read pages

Potential and Kinetic Energy Potential – Water behind a dam – Battery Kinetic – Water moving across turbine blades

A cute picture!

4 Main Types of Energy Chemical Energy Heat Energy Light Energy Mechanical Energy

Chemical Energy A kind of potential energy Energy caused by chemical reactions Examples: – Cooking food – Burning something – Batteries – Matches

Mechanical Energy Mechanical energy is matter in motion. An airplane soaring through the sky has mechanical energy just like the wind or a flowing river. Sound is another type of mechanical energy. Other examples: compressed springs, stretched rubber bands, bow and arrow, hammer and nail

Thermal (Heat) Energy The total of all the kinetic and potential energy of the atoms in an object When any forms of matter gets warmer, the object’s thermal energy increases

Thermal (Heat) Energy Energy pushed into motion by heat Examples: – Insulation – Refrigerators – Air conditioners – The Sun – Stove

Conduction, Convection, and Radiation Read page 465 in your book

Conduction The flow of heat between objects that are touching

Convection The movement of warm liquids or gases to cooler areas

Convection

Radiation The movement of energy by electromagnetic waves

Light Energy Travels in waves It is Electromagnetic Radiation – a combination of electrical and magnetic energy Look at the pictures on page 458 & 459

Light Energy Light energy comes from the Sun. Plants use it to make food and scientists use it to create lasers. Examples: – Light bulb – Fire – The Sun – Flashlight – Firefly/Lightning bug

Let’s look at how lenses can bend light!

Concave and Convex Lenses

Concave Lens Light is bent outward Makes objects look smaller

Convex Lens Bends light rays to make objects look larger Thickest in the middle Magnifying glass is one example

Here’s a short word from our friend, Bill! bM_c4 bM_c4

Major Parts of the Eye

Light Moving Through the Eye

Light and Color

Let your brain rest while you look at this adorable walrus!

matter.htm

Energy

Sound Energy Sound is a wave of vibrations that spreads from its source Frequency- how fast particles are vibrating Read page 454 and 455 to yourself How does your ear work? – WmU8 WmU8

Sound Energy

Now, Let’s Look at a Cute Picture!