Chapter 11, Problem 13STP

To determine

The distance travelled by electromagnetic wave in vacuum in one year.

Answer to Problem 13STP

The required distance travelled is $\boxed{9.45\times {10}^{15}\text{m}}$ .

Explanation of Solution

Given:

Time taken by electromagnetic wave in vacuum to travel in one year is, $t=365\times 24\times 60\times 60=3.15\times {10}^7\text{s}$ .

Formula used:

The distance taken by the wave to travel in vacuum is,

$d=ct$   ..... (1)

Here, $t$ is the time taken by the wave and $c$ is the speed of light.

Calculation:

Substituting $3\times {10}^8\text{m/s}$ for c and $3.15\times {10}^7\text{s}$ for t in equation (1)

  $\begin{array}{l}d=3\times {10}^8\times 3.15\times {10}^7\\ \boxed{d=9.45\times {10}^{15}\text{m}}\end{array}$   .... (2)

Conclusion:

Hence, the distance travelled by the wave is $\boxed{d=9.45\times {10}^{15}\text{m}}$ .