6.4 Microwaved And Infrared Flashcards
Communication to and from satellites uses what wave
Microwaves
How does satellite tv work
Signal from transmitter to space
Picked up by satellite receiver dish and the transmitts signal back to space
Why is there a time delay ?
Because of the long distance
In microwave ovens what has to happen ?
The microwaves Need to be absorbed by water molecules in food
What happens to the water molecules in food ?
Microwaves absorb energy and then transfer it to the water molecules in the food making water heat up then this energy is transferred to other molecules heating up the food
The hotter the object the more what is given out
Infrared radiation
What do infrared cameras do ?
Detect if radiation turns it into an electrical signal which on a screen is a picture
Absorbing ir radiation does what ?
Objects to get hotter ie food getting cooked
What do electric heaters contain ?
A wire that emits ir radiation which is absorbed by air and objects and transferred energy to thermal stores
