Question

If the speed of Light is 3.0?10^8m/s, calculate the distance travelled by light in one year and express it in scientific notation .

Answer 1

$$\begin{gathered} \mathrm{Speed}\mathrm{of}\mathrm{light}=3\times {10}^8\mathrm{m}/\mathrm{s} \\ \mathrm{Now},1\mathrm{year}=365\times 24\times 60\times 60\sec =31536000\mathrm{s} \\ \mathrm{Distance}\mathrm{travelled}\mathrm{by}\mathrm{light}\mathrm{in}\mathrm{one}\mathrm{year}=\mathrm{speed}\times \mathrm{time} \\ =3\times {10}^8\times 31536000 \\ =94608\times {10}^8\times {10}^3 \\ =94608\times {10}^{11} \\ =9.4608\times {10}^{15}\mathrm{m} \end{gathered}$$