The wavelength of the radio photon is 268 m.
Electromagnetic waves travel with the speed of 3×10⁸m/s in vacuum. The speed of a wave <em>c i</em>s related to its frequency<em> f</em> and wavelengthλ as follows:

Thus the wavelength is given by,

Substitute 3×10⁸m/s for <em>c</em> and 1120×10³Hz for <em>f</em>.

Thus the wavelength of the radio photon from an AM station is 268 m
It looks like they are all units of measurement:
FOOT - POUND - NEWTON - METER
With utmost clarity, that is truest of the truths
The simplest answer would be "acceleration due to gravity."
The exact value of this acceleration changes depending on which planet your on (for example).