We know, for an object in motion m=m01−V2c2√
Thus, as v = c, the quantity in denominator becomes zero. Hence the mass of the object becomes infinite.

As we know from Einstein’s mass energy relation, E = mc².
Therefore, ΔE= Δmc²
ΔE = 4 x 10²⁶ Js^-1, c = 3 x 10⁸ ms^-1.
Δm = 4 x 10²⁶ Js^-1/ 9 x 10¹⁶m²s^-2
Δm = 4.44 x 10⁹ kgs^-1.

One of the postulates of Einstein’s Special Theory of Relativity states that all the inertial frames are equivalent to the formulation of laws of physics. Thus, it is suitable for all the inertial frames.

We know, E = mc² and momentum, p = mv
Now, E² – p²c² = m²c⁴ – m²v²c²
Now, we know, m = m01−V2c2√
Therefore, E² – p²c² = m²c⁴(1-v²/c²)
=c⁴m²(1-v²/c²)
Using, m²(1-v2/c²) = m_o² we get
E² – p²c² = m_o²c⁴.

Such a frame, having four coordinates of x, y, z and time t is called the space-time frame. It plays a major role in Einstein’s special theory of relativity.