When a rod moves at a relativistic speed v, its mass
if the rod is moving with relativistic speed v, then mass will be given by,
thus, the mass will increase by the factor of 
option (A) is correct
1
When a rod moves at a relativistic speed v, its mass
if the rod is moving with relativistic speed v, then mass will be given by,
thus, the mass will increase by the factor of
option (A) is correct