Question

Lunar astronauts placed a reflector on the Moon’s surface, off which a laser beam is periodically reflected. The distance to the Moon is calculated from the round-trip time. (a) To what accuracy in meters can the distance to the Moon be determined, if this time can be measured to 0.100 ns?

Answer 1

accuracy in measured value of distance, d' = 0.015 m

Given:

measured time, t = 0.100 ns =
`0.1* 10^(-9) s`

Solution:

To calculate the accurate distance to the moon with the reflected lased beam, the distance can be calculated by utilizing the time taken for one round trip;

t =
`(2d')/(c)` (1)

where,

d' = distance

From eqn (1):

`0.1* 10^(-9) s\ times 3* 10^(8) = 2d'`

d' = 0.015 m