Question

If you were going to invent a new way to power your mobile phone, which type of electromagnetic wave would be most useful to investigate?

Radio waves, because they are high energy and common.

Gamma rays, because they are strong and safe.

X–rays, because they are low energy and safe.

Ultraviolet rays, because they are moderate energy and abundant.

Answer 1

Which can you eliminate ?

Answer 2

Also , this is the math section

Answer 3

According to wikipedia "The Rayleigh criterion dictates that any radio wave, microwave or laser beam will spread and become weaker and diffuse over distance; the larger the transmitter antenna or laser aperture compared to the wavelength of radiation, the tighter the beam and the less it will spread as a function of distance (and vice versa). Smaller antennae also suffer from excessive losses due to side lobes. However, the concept of laser aperture considerably differs from an antenna. Typically, a laser aperture much larger than the wavelength induces multi-moded radiation and mostly collimators are used before emitted radiation couples into a fiber or into space."

Answer 4

I just eliminated an answer choice for you. Two of the other three are obviously wrong.

Answer 5

could be Ultraviolets rays or radio waves?

Answer 6

Dude. radio waves are LONG.

Answer 7

Ill give you a few hints
radio waves are not high energy
gamma rays are not safe
x-rays are not low energy or safe

Answer 8

great way to give the kid his answer >.>

Answer 9

thanks