We can prove that the inertial mass and the gravitational mass should be the same (equivalence principle) from the $f=mg=ma$ then $g=a$, so we have equivalence law! But why we said equivalence ...
Why Gravity attracts all objects with the same speed? Is this question was solved? What is the exact answer?
From what little I know of general relativity, the equality of inertial and gravitational mass is an axiom of the theory. I suspect that this precludes GR from unifying them in the same sense as ...
Does it make sense to talk of the inertial mass of a scalar field? By the equivalence principle, it must be equal to its gravitational mass. We know that the scalar field contributes towards the ...
Possible Duplicate: Why does the mass of an object increase when its speed approaches that of light? A charged particle that is accelerated through a particle accelerator like CERN ...
Possible Duplicate: If photons have no mass, how can they have momentum? I'm sure this question has been asked here before but I wasn't able to find it clearly answered in one q/a session. ...