The period of a simple pendulum is given by
where
L is the pendulum length
g is the acceleration of gravity
If we move the same pendulum from Earth to the Moon, its length L remains the same, while the acceleration of gravity g changes. So we can write the period of the pendulum on Earth as:
where
is the acceleration of gravity on Earth, while the period of the pendulum on the Moon is
where
is the acceleration of gravity on the Moon.
If we do the ratio of the two periods, we get
but the gravity acceleration on the Moon is 1/6 of the gravity acceleration on Earth, so we can write
and we can rewrite the previous ratio as
so the period of the pendulum on the Moon is
Had to look for the options and here is my answer.
These white lights can be actually found in MID-CHANNEL MARKERS kind of bouys. Buoys are actually necessary because they aid in navigation and these come in different colors and each differ in meaning. Hope this answer helps.