Question

Show that the differential version of poynting theorem is given by $\frac{\partial}{\partial t} [U_{mech}+U_{cm}]= -\vec{\Delta}.\vec S$.

Answer 1

The experiment intended to measure the speed of earth in ether. ... Later Albert Einstein in his special theory of relativity explained the negative result of Michelson Morley experiment. According to special theory of relativity, the light travels at same speed in all inertial frames of reference.