Question

According to mass-energy equivalence, energy contained in 1 g of mass is $a\times {10}^{b}J$.
Find $a+b$.

• A. 22

Answer 1

The correct option is A 22
Given that:
Mass, $m=1g={10}^{-3}kg$
Energy contained, $E=a\times {10}^{b}J$

Speed of light is given by:
$c=3\times {10}^{8}m{s}^{-1}$

According to mass energy equivalence, energy contained in the given mass is:
$E=m{c}^2$
$E={10}^{-3}\times {(3\times {10}^8)}^2$
$E=9\times {10}^{13}J$

Comparing with $E=a\times {10}^{b}J$
$a=9$
$b=13$

$\therefore a+b=22$