A laser is a source of very intense, mono-chromatic and unidirectional

1.	A laser is a source of very intense, mono-chromatic and unidirectional beam of light. These properties of a leaser light can be exploited to measure long distances. The distance of the MOON from the Earth has been already determined very precisely using a laser as source of light. A laser light beamed at Moon takes 2.56 seconds to return after reflection at the the moon's surface.How much is the radius of the lunar orbit around the Earth?
Answer» As v = 2d/t ⇒ d = v x t/2 = (3 x 10⁸ x 2.56/2) = 3.84 x 10⁸ m.

A laser is a source of very intense, mono-chromatic and unidirectional beam of light. These properties of a leaser light can be exploited to measure long distances. The distance of the MOON from the Earth has been already determined very precisely using a laser as source of light. A laser light beamed at Moon takes 2.56 seconds to return after reflection at the the moon's surface.How much is the radius of the lunar orbit around the Earth?

Answer»

As v = 2d/t

⇒ d = v x t/2 = (3 x 10⁸ x 2.56/2) = 3.84 x 10⁸ m.