Question

The distance of Andromeda galaxy from earth is 2.4 X 10 22 m. Find the time
taken by light to travel this distance.

Answer 1

Distance of Andromeda galaxy from Earth = 2.4 × 10^22 m.

Speed of light = c = 3 × 10^5 m/s.

We know t = s/v.

=> t = (2.4 × 10^22 m)/(3 × 10^5 m/s)

=> t = (8 × 10^21)/10^5 s

=> t = 8 × 10^16 s.

So, light will take about 8 × 10^16 s to reach Andromeda galaxy.

More:-

• Distance travelled by light in one years is known as light year. It is 9.5 × 10^15 m.
• Light takes only 8 seconds to reach the earth from the Sun. It takes 1.28 seconds to come moon light to Earth.