379,579 views
39 votes
39 votes
A laser beam from Earth is reflected back from a mirror on the Moon in 2.60 s. If the distance between Earth and the Moon is 3.85 × 108 m, calculate the speed of light.

User Rune
by
2.8k points

1 Answer

9 votes
9 votes

\text{speed}=2.96*\text{ }10^8\text{ }\frac{\text{m}}{s}

Step-by-step explanation

the speed of an object is given by:


\text{speed}=\text{ }\frac{dis\tan ce}{\text{time taken}}

then

Step 1

Let


\begin{gathered} \text{Time}=2.6\text{ s} \\ \text{distance}=\text{ 2(}3.85*10^8)=7.7*10^8 \end{gathered}

Now, replace


\begin{gathered} \text{speed}=\text{ }\frac{dis\tan ce}{\text{time taken}} \\ \text{speed}=\text{ }\frac{7.7*10^8\text{ m}}{2.6\text{ s}} \\ \text{speed}=2.96*\text{ }10^8\text{ }\frac{\text{m}}{s} \end{gathered}

so, the answer is


speed_c=2.96*\text{ }10^8\text{ }\frac{\text{m}}{s}

I hope this helps you

User Kubator
by
2.8k points