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Microwave Ovens 1
Microwave Ovens Microwave Ovens
Microwave Ovens 2
Observations About Microwaves Observations About Microwaves
Microwave ovens cook food from inside out
Microwave ovens cook food from inside out
They often cook foods unevenly
They often cook foods unevenly
They don’t defrost foods well
They don’t defrost foods well
You shouldn’t put metal inside them?!
You shouldn’t put metal inside them?!
Do they make food radioactive or toxic?
Do they make food radioactive or toxic?
Microwave Ovens 3
3 Questions about 3 Questions about Microwave Ovens Microwave Ovens
Why do microwaves cook food?
Why do microwaves cook food?
How does metal respond to microwaves?
How does metal respond to microwaves?
How does the oven create its microwaves?
How does the oven create its microwaves?
Microwave Ovens 4
Question 1 Question 1
Why do microwaves cook food?
Why do microwaves cook food?
Microwave Ovens 5
Electromagnetic Spectrum Electromagnetic Spectrum
- Microwaves are a class of electromagnetic waves
Microwaves are a class of electromagnetic waves
Long
Long-
- wavelength EM waves: Radio & Microwave
wavelength EM waves: Radio & Microwave
Medium
Medium-
- wavelength: IR, Visible, UV light
wavelength: IR, Visible, UV light
Sh rt
Sh rt l n th X l n th X r & G mm r & G mm r
Short
Short-wavelength: X wavelength: X-rays & Gamma rays & Gamma-
- rays
rays
Microwave Ovens 6
Water Molecules Water Molecules
Water molecules are
Water molecules are unusually polar unusually polar
An electric field orients
An electric field orients water molec les water molec les water molecules water molecules
A fluctuating electric field