P5.2 Flashcards
What waves are on the magnetic spectrum (in order of increasing frequency).
Radio waves, microwaves, infrared, visible light, ultraviolet, X-rays Gamma rays
What are electromagnetic waves?
Electromagnetic waves consist of oscillating electric and magnetic fields. The fields are oscillating in a direction at 90° to the direction of the wave.
All electromagnetic waves travel through a vacuum at 3 X 10^8 m/s (the speed of light)
What do electromagnetic waves do?
They transfer energy from sources to absorbers. Some waves transfer info.
How do you calculate frequency of a wave
Frequency = wave speed / wave length
How are electromagnetic waves used for communication?
Your phone communicated with trans,otters using microwaves. Microwaves are also used to communicate with satelites and for WiFi and bluetooth systems.
Remote controls use infrared to communicate with televisions.
How are microwaves used to heat up food?
In. Microwave oven, the water and fat in food absorb the microwaves which heats up the outside of food. Conduction transfers energy to the middle.
How are gamma rays useful in medicine?
Gamma rays can kill cancer cells and also bacteria on food
How are ultraviolet rays useful in medicine
It kills bacteria in water
How are X rays useful in medicine
X-rays can kill skin cancer or other cancer cells
Which waves are dangerous and why?
Ultraviolet radiation can damage the DNA in the cells of your skin.
These cells can grow rapidly and cause skin cancer
X-RAYS can also da,age your cells and cause cancer
GAMMA RAYS can also damage or kill the cells in your body.