Question

The energy equivalent of $0.5\text{g}$ of a substance is :

• A. $1.15\times {10}^{13}\text{Joule}$
• B. $0.5\times {10}^{13}\text{Joule}$
• C. $4.5\times {10}^{16}\text{Joule}$
• D. $4.5\times {10}^{13}\text{Joule}$

Answer 1

The correct option is D $4.5\times {10}^{13}\text{Joule}$

The energy equivalent of corresponding to an amount of mass$\left(\Delta m\right)$ of a substance is given as:
$E=\Delta m{c}^2$

Mass $=0.5\text{g}=0.5\times {10}^{-3}\text{Kg}$
Speed of light $\left(c\right)=3\times {10}^8\text{m/s}$

So, $E=0.5\times {10}^{-3}\times (3\times {10}^8{)}^2$
Therefore, $E=4.5\times {10}^{13}\text{Joule}$.