Chapter SH, Problem 12.8APP

To determine

To calculate: Distance between Earth and moon.

Answer to Problem 12.8APP

Distance between Earth and moon is $\underset{\_}{384000\text{ km}}$ .

Explanation of Solution

Given:

Time taken for the laser to be reflected back = $2.56\text{ s}$

Speed of laser beam = $300,000\text{ km/s}$

Formula used:

Speed for a reflection is given by,

  $v=\frac{2d}{t}$

where dis distance and tis time.

Calculation:

Distance is calculated as:

  $\begin{array}{l}v=\frac{2d}{t}\\ d=\frac{v\cdot t}{2}\\ d=\frac{300000\text{ km/s}\times \text{2}\text{.56 s}}{2}\\ d=384000\text{ km}\end{array}$

Conclusion:

Distance between Earth and moon is $\underset{\_}{384000\text{ km}}$ .