Question

Calculate the energy equivalent of 1 g of substance.

Options

• \[9 \times 10^{16} \text{ J}\]

• \[9 \times 10^{13} \text{ J}\]

• \[3 \times 10^{13} \text{ J}\]

• \[9 \times 10^{11} \text{ J}\]

Answer 1

Using \[E = mc^2\] with \[m = 10^{-3} \text{ kg}\] and \[c = 3 \times 10^8 \text{ m s}^{-1}\]: \[E = 10^{-3} \times (3 \times 10^8)^2 = 10^{-3} \times 9 \times 10^{16} = 9 \times 10^{13} \text{ J}\].