If a mass of 3.6 g is fully converted into energy, how many kilowatt hour of electrical energy will be obtained ?

Explanation

The energy obtained is
`E = mc^(2) = (3.6 xx 10^(-3) kg ) (3 xx 10^(8) m s^(-1) ) ^(2) = 32.4 xx 10 ^(13) J.
Now 1 kilowatt hour `= 10^(3) J s ^(-1) xx 3600 s = 3.6 xx 10(6) J`.
Thus , `E = 32. 4 xx 10^(13) / 3.6 xx 10^(6) kWh = 9 xx 10^(7) kWh.