Question

The energy produced when 1 kg of a substance is fully converted into energy is ............

• A. $9\times {10}^{16}J$
• B. $9\times {10}^{8}J$
• C. $18\times {10}^{8}J$
• D. $18\times {10}^{16}J$

Answer 1

Answer: (A)

$9\times {10}^{16}J$

$E=m{c}^2=1\times {(3\times {10}^8)}^2=9\times {10}^{16}J$

The energy produced when 1 kg of a substance is fully converted into energy is $9\times {10}^{16}J$.

The energy ($E$) of a mass to energy conversion equals the mass ($m$) that was converted multiplied by the speed of light ($c$) squared. If we choose mass in kilograms and the speed of light in meters per second, then the answer will be in joules. Basically, the equation states that matter and energy are identical. If you could convert a small amount of matter completely, it would yield a tremendous amount of energy.