**·**2013-08-20 11:14:21

Photons have mass when they travel at the speed of light. Their rest mass is zero. So, considering that apply the formula m_{0}/sqrt(1-(v2/c2) and you will find that it comes to 0/0. This means at the speed of light, photons can have any mass whatsoever, ranging from 0 to infinity (since 0/0 has infinite answers).

Thanx...

- Asmita Chatterjee but how come photons even have mass wen they r travelling at the speed of light.how can they travel at such high velocity if they have mass.i dont understand....

·0·Reply·2013-08-22 09:46:10