Question

Mars is roughly 60 million km from earth. How long does it take for a radio signal originating from earth to reach mars?

Short answer

Answer

The time taken for a radio signal originating from earth to reach mars is 200 sec.

Step-by-step solution

Step 1:

(Writing out known values)

Displacement of radio signal$\mathit{∆}s\mathit{=}\mathit{60}\mathit{\times }{\mathit{10}}^{\mathit{9}}m$

The velocity of the radio signal,$v\mathit{=}\mathit{2}\mathit{.}\mathit{998}\mathit{\times }{\mathit{10}}^{\mathit{8}}m\mathit{/}s$

Step 2:

(Calculating the time it takes for a radio signal to reach Mars from the earth)

$$\begin{gathered} \mathit{∆}t\mathit{=}\frac{\mathit{∆}\mathit{s}}{\mathit{v}} \\ \mathit{∆}t\mathit{=}\frac{\mathit{60}\mathit{\times }{\mathit{10}}^{\mathit{9}}\mathit{m}}{\mathit{2}\mathit{.}\mathit{998}\mathit{\times }{\mathit{10}}^{\mathit{8}}\mathit{m}\mathit{/}\mathit{s}} \\ \mathit{}\mathit{}\mathit{}\mathit{}\mathit{=}\mathit{2000}sec \end{gathered}$$