Question

Imagine that a reactor converts all given mass into energy and that it operates at a power level of ${10}^{9}W$. The mass of the fuel consumed per hour in the reactor will be (velocity of light, c is $3\times {10}^{8}m/s$)

• A. $0.8gm$
• B. $0.96gm$
• C. $4\times {10}^{-2}gm$
• D. $6.6\times {10}^{-5}gm$

Answer 1

The correct option is C $4\times {10}^{-2}gm$

Energy converted in one hour = $p\times t$

$={10}^9\times 3600sec$

$=36\times {10}^{11}J$

Mass of fuel consumed in one hour is

$M=\frac{E}{c^2}$

$M=\frac{36\times {10}^{11}}{(3\times {10}^8{)}^2}$

$M=4\times {10}^{-5}kg=4\times {10}^{-2}gm$