Question

The distance of the moon to the Earth is 384,400 km.

The speed of light is 2.998 x 108 m/s.
Work out how long it will take light to travel from the moon to the Earth.
Include suitable units.

Answer 1

Answer: 1.3 seconds

Explanation:

Given: Distance of the moon to the Earth = 384,400 km = 384400 x 1000 meters = 384400000 meters. [1 km = 1000 m]

Speed of light =
`2.998 * 10^8` m/s = 299800000 m/s

Formula:
`\text{Time}=\frac{\text{Distance}}{\text{Speed}}`

Let t be the time taken by the light to travel from the moon to the Earth.

`t=(384400000)/(299800000)\approx1.3\text{ seconds}`

Hence, it will take approximately 1.3 seconds for the light to travel from the moon to the Earth.