# Photon problems

1. Aug 31, 2005

### vietcuong

the energy of photon is given e=hf, but when we consider this with doppler effect of the source goes far away from the receiver.it seems that the energy of photon is decreased. (which contradicts the conservation of energy
in reality :is this argument true?
if it happened, what would result with the conservation of energy
if it were wrong , how can we reject our calculations and expression :surprised

2. Aug 31, 2005

### ZapperZ

Staff Emeritus
The energy of a ball moving with velocity v is $$1/2 mv^2$$. Yet, if you're moving in the same reference frame of the ball, the ball has no KE. Do you think there's an energy conservation violation here too?

Zz.