Question

If I completely annihilate a hair of your body that has a mass of $1\mu g$ then how much energy will I get in the process.

• A. $9\times {10}^{10}J$
• B. $8\times {10}^{10}J$
• C. $9\times {10}^{12}J$
• D. $8\times {10}^{6}J$

Answer 1

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

Mass is a condensed form of energy. Einstein's theory says that if we have a mass m then it's actually made up of certain amount of energy E and $m=\frac{E}{c^2}$Hence if we anihilate a mass m, according to this equation, the amount of energy that we'll get is :
$E=m{c}^2$
Now we have a mass = $1\mu g$
Hence energy $E={10}^{-6}\times (3\times {10}^8)\times (3\times {10}^8)J$
Which is on calculating $9\times {10}^{10}J$
Quite a good amount of energy!!!