P1 Cooking and communicating using waves

P1 Cooking and communicating using waves

1. Cooking with waves

   • Infrared radiation does not penetrate food very easily
   • Microwaves penetrate up to 1cm into food
   • Microwaves can penetrate glass or plastic but are reflected by shiny metal surfaces; special glass in a microwave over door reflects microwaves and they can cause body tissue to burn

2. Microwave communication

   • Microwave radiation is used to communicate over long distances
   • The transmitter and 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
   • There are concerns about the use of mobile phones and where phone masts are situated
   • Scientists publish results of their studies to allow others to check their findings