I'm in a spaceship very far away from earth but traveling straight towards earth with a speed v. It's boring out here, so I decide to try and tune in to some of my favorite earthly radio stations. I remember that my favorite station has a frequency of 100.3 MHz and so tune my radio to exactly this frequency. Amazingly, I hear the radio station just like I do on earth! How fast is my spaceship going in m/s? (Hint: it's not that fast...I think I should check whether my engines are on).
Details and assumptions Photons of electromagnetic radiation have an intrinsic kinetic energy related to their frequency by E=hf where h is Planck's constant. The gravitational interaction between photons and earth can be treated via usual Newtonian gravity and E=mc2 to convert between energy and mass. The total energy of the photons is conserved. The earth can be treated as a sphere of radius 6370 km and mass 6×1024 kg. You can ignore rotation of the earth. The speed of light is 3×108 m/s.
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Comments
Cheating!
Careful with your posts, you might get demerits (or even worse, i hope not).
don't just copy paste a problem which everyone can already see also giving hints would be cheating
did you get the answer
Is it related to doppler effect ?