
Jim L. answered 04/28/21
Personable, effective English, Math and Science Tutor
Hi Sam,
The equation you need is relatively simple
Wavelength X frequency = velocity
In this case, the velocity of an electromagnetic wave is the speed of light (I use 3 x 10^8 m/sec)
So F - 3x10^8/4.35x10^-9 = 6.89m