Question

does inertia of a body depends on its energy content?

Answer 1

Inertia is not dependent on the energy of a body. Inertia is defined as the property of a body to continue to be at rest or in uniform motion until it is disturbed by an external force. It is measured in terms of mass, i.e. kilogram. However, if the body is moving with a velocity close to the velocity of light, then its mass increases. Hence, inertia of the body increases for relativistic energy.