Question

a particular star is at the distance of about 8.1×10 power13 km from the earth.assuming that the light travels at 3× 10 power8 m/sec,find how long does light takes from that star to reach the earth

Answer 1

Answer:

2.7 x 10^8 s

Step-by-step explanation:

Given a particular star is at the distance of about 8.1×10^13 km from the earth.assuming that the light travels at 3× 10^8 m/sec,find how long does light takes from that star to reach the earth

Given distance between earth and star is 8.1 x 10^13 km. We know that light travels at a distance of 3 x 10^8 m/s.

1 km = 1000 m = 10^3 m

So we need to find the time taken by light to reach the earth  

So speed = distance / time

Time = distance / speed

8.1 x 10^13 x 10^3 / 3 x 10^8

8.1 x 10^16 / 3 x 10^8

8.1 x 10^8 / 3

2.7 x 10^8 secs            

Answer 2

Answer:

This is 100 % correct ans in my book at back this is only the answer