Question

(a) Neil A. Armstrong was the first person to walk on the moon. The distance between the earth and the moon is 3.85 x 108 m. Find the time it took for his voice to reach earth via radio waves. (b) Someday a person will walk on Mars, which is 5.6 x 1010 m from earth at the point of closest approach. Determine the minimum time that will be required for that person's voice to reach earth.

Answer 1

Answer:

a). 1.28333 seconds

b). 186.66 seconds

Explanation:

a). Given :

Distance between the earth and the moon, d = $3.85 \times 10^8$ m

Speed of the radio waves, c = $3 \times 10^8$ m/s

Therefore the time required for the voice of Neil Armstrong to reach the earth via radio waves is given by :

$t=\frac{d}{c}$

 $=\frac{3.85 \times 10^8}{3 \times 10^8}$

 = 1.28333 seconds

b). Distance between Mars and the earth, d = $5.6 \times 10^{10}$ m

   Speed of the radio waves, c = $3 \times 10^8$ m/s

So, the time required for his voice to reach earth is :

$t=\frac{d}{c}$

 $=\frac{5.6 \times 10^{10}}{3 \times 10^8}$

 = 186.66 seconds