The speed of all electromagnetic waves in

empty space is 3.00 × 108 m/s. What is the wavelength of visible light emitted at 7.2 × 108 MHz?
Answer in units of m

1 answer

frequency f = 7.2 × 10^8 MHz
= 7.2*10^14 Hz

Wavelength (m) = (speed of light, m/s)/(frequency, Hz)
= 3.00*10^8/7.2*10^14 = 4.17*10^-7 m
= 417 nm

That correspnds to violet light