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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!
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