Question

The approximate value of the velocity of light in vacuum used in the mass-energy equivalence relation is:

Options

• \[c \approx 3 \times 10^{10} \text{ m s}^{-1}\]

• \[c \approx 3 \times 10^6 \text{ m s}^{-1}\]

• \[c \approx 9 \times 10^{16} \text{ m s}^{-1}\]

• \[c \approx 3 \times 10^8 \text{ m s}^{-1}\]

Answer 1

The velocity of light in vacuum is approximately \[3 \times 10^8 \text{ m s}^{-1}\]. Squaring this value in \[E = mc^2\] gives the very large factor \[9 \times 10^{16}\], which multiplies the mass to yield its energy equivalent.