Changing Forms of Energy

Chap

ter 1

4

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 448-451

http://www.youtube.com/watch?v=T5WJoup-RD8

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!

• http://www.youtube.com/watch?v=fD1544bM_c4

Major Parts of the Eye

Light Moving Through the Eye

https://www.youtube.com/watch?v=syaQgmxb5i0

Light and Color

• http://www.youtube.com/watch?v=AD1Xic2mn0U

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

http://studyjams.scholastic.com/studyjams/jams/science/matter/energy-and-matter.htm

Energy

• http://www.youtube.com/watch?v=btLU2lb3-xs

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?– http://www.youtube.com/watch?

v=HMXoHKwWmU8

Sound Energy

http://www.youtube.com/watch?v=lTetdgpu7MU

Now, Let’s Look at a Cute Picture!