Question

In the book,the distance between two planets is given as 4.07×10^¹² kilometres. The speed of light is 1.1×10^⁹ kilometres per hour. Calculate the time taken for light to travel from one of these planets to the other. Give your answer in days and hours.

Answer 1

3700hours

154days

Explanation:

Speed can be defined as the distance cover per time, it can be expressed as

Speed= distance/ time........eqn(1)

Given:

distance between two planets= 4.07×10^¹²

speed of light = 1.1×10^⁹ kilometres per hour

Time= ??

Then substitute the values into equation (1) we have

Speed= distance/ time

1.1×10^⁹ kilometres per hour= 4.07×10^¹²kilometre/ time

Cross multiply, we have

Time= (4.07×10^¹²kilometre) /(1.1×10^⁹ kilometres per hour)

Time= 3700hours.

To convert to day, we know that

60 minute= 1hour

24hour=1day

Time= (3700hour×1day)/24hour

Time= 154days approximately.

Hence, the time taken for light to travel from one of these planets to the other is 154days or 3700hours