Question

Can someone explain to me how to answer this problem in simple ways? (I get really confused when it comes to math) A communications satellite transmits a radio wave at a frequency of 5 • 109 Hz. What is the signal’s wavelength? Assume the wave travels in a vacuum.

Answer 1

When I find a problem like this, I find it helpful to think about what I know and what equation will help me.

The question tells us the frequency of the wave $(5 \times 10^{-9})$ Hz. We want to work out the wavelength. What equation links these two quantities?

Wave Speed = Frequency x Wavelength
(we know all electromagnetic waves travel at the speed of light in a vacuum)

$(3 \times 10^8) = (5 \times 10^{-9}) \times \lambda$
and then divide by $(5 \times 10^{-9})$ to get the wavelength.

Wavelength = $6 \times 10^{16}$ m<u />