Question

We kwow momentum p= mv
But mass of photon is m=0
Then give the definition of photon momentum??

Answer 1

actually momentum equation original mass of body multiply with their velocity . but in case of photon rest mass is zero not real mass zero . this is not possible any particle exist without mass . but it is possible rest or relative mass is zero .
rest mass of photon is zero due to if we compared its mass with proton then we see that photon mass very -very less then proton mass .
so, this reason photons have momentum .