Optics

1
Optics

• What is Light?

2
Light

• A wave of energy that travels in straight lines
  which illuminates things.

3

• Light travels at 300 000 km per second. (or 3
  000 000 000 m per second)
• If light circled around the surface of the earth,
  it would travel 71/2 times around the earth in
  one second.

4
travels through different types of mediums
(materials)

• Transparent mediums
• - All light passes through
• Eg. Window (plate of glass)

5

• 2. Translucent
• - some light passes through, but not all
• Eg. Stained glass

6

• 3. Opaque
• - no light passes through object
• Eg. Wood, walls (drywall/cement)

7
Class Activity

• Can you think at least 3 everyday objects of
  each transparent, translucent and opaque?

8

• There are many different types of light emitted.
  The wave of each type has a different wavelength.

9
Electromagnetic Waves
DO NOT COPY DOWN

• Believe it or not, you are being showered all
  the time, not by rain but by waves.

10

• All waves are included on Electromagnetic
  Spectrum

11
Different Wave Uses

1. Radio waves TV signals, Cell phones
2. Microwaves microwaves, radar guns
3. Infrared waves burglar alarms, infrared goggles,
   night vision
4. Visible Waves Rainbows, Astronomy, human vision
5. Ultraviolet waves Disinfect drinking water, Sun
   Rays, detective work, Gone in 60 Seconds car list
6. X-rays Customs at airports to check luggage
7. Gamma rays Very dangerous, used to kill
   cancerous cells

12
Infrared Demo

• Who has a cell phone?

13
Visible Light Spectrum

• Light waves that we can see
• Different wavelengths emit different colours.
• ROY G. BIV are the colours we can see, if all
  wavelengths are shone together, white light is
  produced.

14
Spectroscopes

• Can you see the colours?

15
Colour Wavelengths
16
Pg. 429 2 5