makes

two orbits around the Earth per day. Each satellite transmits a $50\mathrm{.}0$ sinusoidal

electromagnetic signal at two frequencies, one of which is $1575\mathrm{.}42.$ Assume that a

satellite transmits half of its power at each frequency, and that the waves travel uniformly in

a downward hemisphere.

a$.$ What average intensity does a GPS receiver on the ground, directly below the satellite,

receive? $($Hint: for satellites in Earth orbit, the gravitational force

supplies the centripetal force for the satellite to remain in orbit$).$

b$.$ What are the amplitudes of the electric and magnetic fields at the GPS receiver