According to the theory of relativity, mass can be transformed into...

Let $E = k m^a c^b$, where $k$ is a dimensionless constant.

Writing the dimensional formula of each physical quantity:

$[E] = [M L^2 T^{-2}]$

$[m] = [M]$

$[c] = [L T^{-1}]$

Substituting the dimensions in the assumed relation:

$[M L^2 T^{-2}] = [M]^a [L T^{-1}]^b$

$[M L^2 T^{-2}] = [M^a L^b T^{-b}]$

Equating the powers of $M$, $L$, and $T$ on both sides:

$a = 1$

$b = 2$

$-b = -2 \Rightarrow b = 2$

Substituting the values of $a$ and $b$ in the assumed relation:

$E = k m^1 c^2$

$E = k m c^2$