Question

When ${}^{92}{U}_{235}$ undergoes fission 0.1% of its original mass is changed into energy. How much energy is released if 1 kg of ${}^{92}{U}_{235}$ undergoes fission

• A. $9\times {10}^{10}J$
• B. $9\times {10}^{11}J$
• C. $9\times {10}^{12}J$
• D. $9\times {10}^{13}J$

Answer 1

The correct option is D $9\times {10}^{13}J$

$\Rightarrow \frac{0.1}{100}\times 1㎏=\frac{1}{1000}㎏={10}^{-3}㎏$

Using the equation

$E=m{c}^2$

$={10}^{-3}\times {(3\times {10}^8)}^2$

$={10}^{-3}\times 9\times {10}^{16}$

$E=9\times {10}^{13}J$