The most dangerous frequencies of electromagnetic energy are X-rays, gamma rays, ultraviolet light and microwaves. X-rays, gamma rays and UV light can damage living tissues, and microwaves can cook them. Hope this helps! =^-^=
Metal detectors work by transmitting an electromagnetic field from the search coil into the ground. Any metal objects (targets) within the electromagnetic field will become energised and retransmit an electromagnetic field of their own.
Answer:
speed = distance/time
just find the speed if it