Light & Beyond

Inductiveload, NASA [GFDL (http://www.gnu.org/copyleft/fdl.html) or CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0/)], via Wikimedia Commons

The S3 Physics Block covers Beyond the Visible after covering light. Attached is the outcomes that you should cover in your course.

The Electromagnetic Spectrum

The electromagnetic (em) spectrum is a collection of transverse waves that all travel at the same speed in air, the speed of light, 300 000 000 m/s. (equivalent to 7.5 times round the Earth every second)

One of the waves is VISIBLE LIGHT

A=amplitude λ = wavelength

Others are RADIO & TV, MICROWAVE.

The others are INFRA-RED, ULTRA VIOLET, X-RAYS, GAMMA WAVES.

The only difference between each of these waves is their wavelength or frequency. They all fit the formula

Speed= frequency × wavelength

v=f λ

The order is important and to remember it use the following rhyme!

Randy                  Radio & TV

Monkeys              Microwaves

Invade                 Infrared

Venezuela           Visible

Using                   Ultraviolet

Xylophone           X-rays

Gunships             Gamma

Period, T, is the time for one wave to pass a point and is measured in seconds.

Frequency, f is the number of waves being produced or passing a point per second. Frequency is measured in Hertz (Hz)