Question

How long would it take light to travel round trip to Mars when it is 2x1010m from the Earth?

a) 0.015s
b) 0.03s
c) 66.7s
d) 133s

Show calculation

Answer 1

66.7s

Step-by-step explanation:

Given parameters:

Distance between Mars and Earth = 2 x 10¹⁰m

Unknown:

Time it takes for light to travel = ?

Solution:

The speed of light is given as 3 x 10⁸m/s

Now;

Speed =
`(distance)/(time)`

Time =
`(distance)/(speed)`

Insert the parameters and solve;

Time =
`(2 x 10^(10) )/(3 x 10^(8) )` = 66.7s