# Electromagnetic waves part 1

Mindmap about electromagnetic waves, their uses, sound and ultrasound, wavelength and frequency

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• Electromagnetic waves
• Different waves
• Granny's Xbox uses volts in my room
• Gamma, X-rays, UV light, visible light, Infrared, microwaves, radiowaves
• Shortest wavelength= Gamma (approx -10 to the power of 15) longest wavelength= radio (can range to over 10,000m
• All waves travel at the same speed, they have different wave lengths and frequencies
• Wavelength and frequency
• Wave length
• Distance between crests in waves
• Frequency= Wave speed/ Wavelength
• How many waves pass a certain point in a period of time
• Period of time is just called the period
• F=V/ Lambda
• This can be made into a triangle
• Crest is the top of a wave
• The length of one full wave
• Frequency
• How many waves pass a certain point in a period of time
• Period of time is just called the period
• Wave uses
• Visible light- See these. See  the different wavelengths as colours
• Infrared- Given off by all objects. More heat= more infrared
• Used in  Remote controls
• Skin burns
• Microwaves- used in communications, Mobile phones
• Heating body temperature ( can harm health)
• Gamma- Kill cancerous cells
• Genetic mutations
• X- rays- X ray scanners
• Can kill cells in large doses
• Cause ionisation
• UV- security marking
• Skin cancer and blindness
• Sound and ultrasound
• Sound waves are longitudinal
• Waves vibrate in the same direction they are moving
• PUSHING a spring
• Pitch determined by frequency and amplitutde
• Amplitude is distance between line and crest
• Can be reflected or refracted
• Ultrasound
• Sound energy with frequency higher than human hearing range
• We can  see how far away something is by beaming ultrasound at it and seein how long it takes to reach us again
• This distance can be calculated
• Distance= Wave speed x time taken
• S=V x T
• Ultrasound can be used to scan and destroy kidney stones
• Gamma, X-rays, UV light, visible light, Infrared, microwaves, radiowaves