1. Energy Energy – the ability or the capacity to do work
Energy can only be observed as it changes.
During a change one body will usually gain energy while another will lose energy.

2. Kinds of Energy Electrical energy – energy in an electrical current.
Kinetic Energy – energy of motion or a moving body.
Potential Energy – energy that a body has because of its position or state.

3. How do you know how fast molecules are moving in a substance?
Thermometers measure how fast or slow molecules move. Heat energy also known as thermal energy is what thermometers are actually measuring.
You can convert from one temperature scale to another by using the ESRT pg Just travel across the scales to see equivalent temperatures but be careful… one scale does not count using the same increments as the others…

4. Electromagnetic Energy

5. This type of energy can travel through empty space.
Everything gives off EM energy – the amount depends on the object’s temperature.
Objects giving off energy are known as the source and the object it is going into is known as the heat sink.

7. Types of EM Energy reaching the surface of the Earth.
Radio and visible light waves are the only types that will reach the Earth’s surface.

8. How long are the wavelengths?

9. Absolute Zero
The temperature at which an object is not radiating energy (all molecules stop motion).
This is a theoretical temperature since we can determine the temperature of all objects.
It is 0 degrees on the Kelvin scale.

10. Basic properties of waves :
Energy is transferred from one place to another in a wave motion.

11. Electromagnetic Waves
Disturbance of electric and magnetic fields travelling through space.
All electromagnetic waves are transverse waves.
examples
X-rays, radio waves, micro-waves,etc.

12. The amplitude is the height of the wave measured from the resting point.
The wavelength () is the minimum distance between two points (either 2 crests or 2 troughs).
The frequency (ƒ) is the number of complete waves made in one second Unit : Hz

13. Four things can happen when waves come into contact with matter.
Refracted
Reflected
Scattered
absorbed

14. Reflection of Waves
A travelling wave is reflected when it hits a barrier.
This phenomenon can easily be observed when a travelling water wave hits a reflector in the ripple tank.
Reflector
Reflected
waves

15. Refraction of Waves
- The speed of a water wave increases with depth. This change in speed is accompanied by refraction.
Refraction is the bending of the waves when it changes from one medium to another.

16. What color shirt would you wear on a hot summer day?
Waves may also be
Scattered when they hit a surface (especially if it is uneven.)
absorbed – taken in by the object (especially if it is dark colored and rough in texture.
What color shirt would you wear on a hot summer day?

17. The sun: our main source of energy

18. Most of the energy from the sun is in the form of invisible waves.
Ultraviolet radiation, which is responsible for sunburns, is sent to us from the sun. UV is also useful for those cool black light effects where your white shirt (and lint) glows.
Infrared is really just heat. The hotter something feels the more infrared energy that object is giving off. Objects that are good absorbers of energy are also good radiators.

19. The solar corona as seen in deep ultraviolet light at 17
The solar corona as seen in deep ultraviolet light at 17.1 nm by the Extreme ultraviolet Imaging Telescope instrument aboard the SOHO spacecraft

20. An infrared image of the space shuttle as it lands – notice how the underside of the shuttle is showing its extreme temperature with the change in color.
An infrared image of a person. In this image red is the highest temperature followed by yellow, then green and blue (the coolest).

21. All objects emit radiant energy (heat)
(except at absolute zero (-459o F)
Our Sun emits ALL forms of radiation

22. Radiation
Maximum Energy from the Sun is in the form of Visible Light (Short waves)
Maximum Energy from the Earth is in the form of Infrared (longer waves)