Question

A space probe on the surface of mars sends a radio signal back to earth,a distance of 7.19 ×10⁷ km. Radio travel at the speed of light (3.00 ×10⁸ m/s). How many seconds does it take for the signal to reach the earth?

Answer 1

Answer:

The time taken by the signal to reach the earth is 240 s.

Explanation:

As it is known that speed of any particle is defined as the rate of change in distance per unit time. So depending upon how much distance is covered in a given time, the speed of that travelling particle can be determined. In this case, the distance to be covered is given as $7.19*10^{7}$ km . And it is also known that any radio signal travels with the speed of light. So the speed or velocity of the signal is given as $3*10^{8}$ m/s. Thus, $Speed = \frac{Distance}{Time}$. So, $Time =\frac{Distance}{Speed}$. Since the distance is given in km, we have to convert it to meter.

Thus,$Time = \frac{7.19*10^{7}*10^{3} }{3*10^{8} }$.

So,$Time = 2.397*10^{7+3-8}=2.397*10^{2}=240 s$.

Thus, nearly 240 s are required by the signal to reach the earth.