# Why mass of the object increases as object approaches the speed of light? Does matter of body increases? Give some intuitive explanation?

Please give a qualitative explanation, as opposed to $E = mc^{2}$ or the Lorentz equation of mass. Does the matter of body, i.e. the number of atoms, increase?

• The mass of the object does not increase: it is and always stays $m_0$. A corrective factor $\gamma$ for the velocity is present though in front of the equations of motion, but the mass remains the same. Aug 30 '16 at 7:44

What changes isn't its actual mass - that is defined by its rest mass. What increases is something called its relativistic mass. As the velocity of a body asymptotically approaches $c$, it may be helpful to think of an "acceleration" preventing the velocity from every reaching $c$. Naturally, this "acceleration" may be expressed as a "force" divided by a "mass". This "mass" is the relativistic mass.