Cooking and communicating with waves

Cooking and communicating with waves

1. Infrared radiation does not penetrate food very easily

2. Microwaves penetrate up to 1 cm into food

   • Microwave radiation is absorbed by water and fat.
     • Microwaves can penetrate glass or plastic but are reflected by shiny metal surfaces: special glass in a microwave oven door reflects microwaves and they can cause body tissu to burn

3. Electromagnetic spectrum of waves include radio waves, microwaves, infrared, visible light, ultraviolet light, x-rays and gamma rays

   • All electromagnetic waves travel with the same speed in a vacum
     • Objects emit radiation due to their temperature.hot objects emit a range of different types of electromagnetic radiation

4. Microwave radiation is used to communicate over long distances.the transmitter or receiver must be in line of sight

   • Satellites are used for microwave communication.the signal from earth is received, amplified and re-transmitted back to earth. moreover they are in line of sight because there are no obstructions in space so therefore large airels can handle thousands of phone calls and television channels at once