EMS WavesSection 2

Coach Smith

What is the EM Spectrum0We learned in section 1 that all EM waves travel at the

same speed in a vacuum (empty space), but their wavelengths and frequencies are different.

0Because of these differences each type of wave have different properties.

0There is an inverse (opposite) relationship that exist between WL and F.

0As the length of a wave decreases its frequency goes increases.

0The EMS is placed in order from lowest frequency (Radio waves) to the highest frequency (Gamma Rays)

Radio Waves

0Radio waves: are EM waves with the longest wavelength and lowest frequency. These waves are used to broadcast signals for radio and television.

0A Radio will absorb the Radio wave and transform the wave into an electrical signal

Microwaves

0Microwaves: are Radio waves with the shortest WL and highest frequencies.

0Microwaves are used to heat food, cell phone communication, and radar

0Radar (radio detection and ranging), this system uses reflected radio waves to detect objects and measure their distance and speed.

Infra[red]

0 Infrared waves are detected through heat given off by an object.

0These waves are used by fast food industries to keep food warm

0Thermogram is an image that shows regions of different temperatures in different colors. The blue/purple colors would be the coolest and the yellow/orange/red areas are the warmest

Visible Light

0These are the waves that you can see0The VL waves with the longest wavelength appears

Red while the VL wave with the shortest wavelength appears Violet.

0The colors in order from longest to shortest wavelengths are R O Y G B (I) V

0These colors are seen when White light waves from the sun are refracted and the light separates into those colors.

Ultraviolet Rays

0This wave carries enough energy to damage or kill living cells. UV lamps are often used by hospitals to kill bacteria on hospital equipment.

0Small doses are useful. They can cause your skin cells to produce Vitamin D which is needed for healthy bones and teeth.

0To much exposure can cause skin cancer and damage your eyes.

0To prevent wear sunblock and sunglasses

X-Rays

0These rays carry enough energy to penetrate most matter except dense matter like Bone and Teeth, and the lead vest the doctor will lay across you when taking X-rays

0Too much can cause cancer0X-rays also have industry uses (the Hubble telescope

uses X-rays to detect black holes and far off galaxies)

Gamma Rays

0These rays have the shortest wavelength and highest frequency.

0These rays can penetrate any substance because of there high energy level

0Hospitals use Gamma rays to kill cancer cells inside the body

0Our atmosphere blocks out gamma rays