Question

The distance of a galaxy from the earth is 5.6 × 10 to the power 25 metres assuming the speed of light to be 3 × 10 to the power 8 metres s to the power minus 1 find the time taken by light to travel this distance

Answer 1

we have a formula

Speed=distance/time

time=distance/speed

=5.6×10^25/3×10^8

t =1.86×10^17 sec