Question

We have E=mc².

Generally kinetic energy of anything is ½mv².

So shudnt it be E=½mc² instead of just mc²?? Where.. m is mass and and c is the velocity??🤔

Answer 1

The inertial mass of a body is increased through the absorption of radiation (heat) and decreased through emission by the heat number divided by the speed of light squared (vacuum ). Mass(mechanical) = E(heat)/C^2 that is either gained or lost through absorption or emission.

James Maxwell determined that radiation impresses a pressure on material mass. Friedrich Hasenohrl and Max Planck figured out, directly the basis of Henri Poincaré’s work, that radiation absorbed by a body increases its mass by E/c^2. Therefore, the mass-energy relation.



as you can see in relativity theory mass is not a constant .but usually we consider mass as constant .

for knowing more about this topic we must have a strong base in relativity theory .

physics have different branches ,2 of them are quantum mechanics and kinematics physics
in quantum mechanics wee deal with small particle like protons etc.
in kinematics wee deal with larger particles like car ,heavy weights etc
these both branches have difrent theories .
that brings the difference in both equations