Question

The energy equivalent to a substance of mass $1g$ is

• A. $18\times 10^{13}J$
• B. $9\times 10^{13}J$
• C. $18\times 10^{6}J$
• D. $9\times 10^{6}J$

Answer 1

Answer: (B)

Given, $m=1g=10^{-3}kg$
Energy, $E=m{c}^2$
$\therefore$ Energy equivalent $={\left(10\right)}^{-3}\times {\left(3\times {\left(10\right)}^8\right)}^2$
$\left(\because c=3\times {\left(10\right)}^{8}m{\left(s\right)}^{-1}\right)$
$=9\times 10^{13}J$