Question

What is the wavelength of a radio photon from an "am" radio station that broadcasts at 1280 kilohertz?

Answer 1

Working formula:

Wavelength = wave velocity/frequency
                 λ = v/f


Given:
frequency (f) = 1280 kilohertz (Note: Hertz = cycles per second)
wave velocity or sound velocity (v) = 340 m/s 

Required: Wavelength (λ)

Solution:
Considering the formula above,

λ = v/f
λ = (340 m/s)/(1280*1000 cycles/s)
λ= 2.65625 x 10^-4 m


ANSWER: 0.000265625 m or 2.65625 x 10^-4 m

Answer 2

The wavelength of the given wave is calculated through the equation,
      λ = c/v
where λ is the wavelength,
           c is the speed of light, equal to 3x10⁸ m/s, and 
           v is the frequency

Then, we substitute the known values to the equation,
     λ = (3 x 10⁸ m/s)/(1280 x 10³/s) 
    λ = 234.375 m

The wavelength of the "am" radio station is 234.38 m.