Question

second
nental
3. The distance of a galaxy from the earth is 5.6 x 1025 m.
Assuming the speed of light to be 3 x 108 m s-1
find the time taken by light to travel this distance.
Distance travelled
[Hint : Time taken
speed
]​

Answer 1

Answer:

2 ×10¹⁷ seconds

Explanation:

Speed = distance travelled/ time taken

∴ speed of light = distance travelled / time taken

∴ 3 ×10⁸ m/s = 5.6 ×10²⁵m / time taken

∴time taken =  5.6 ×10²⁵m / 3 ×10⁸ ≈ 2 ×10¹⁷ seconds