How long must a pendulum be to have a period of 2.3 seconds on the Moon where gravity = 1.6m/s^2?

Question

I don't understand this question.
Please help me.

Answer 1

There is an equation for the period of a pendulum:

T = 2 pi sqrt (L /g )

where
T = period = 2.3
pi = 3.14
L = length
g = gravity acceleration = 1.6

if we solve the equation for Length we get

L = T^2 g / 4 pi^2

L = 2.3^2 x 1.6 / 4 x 3.14^2 = 0.215 meter = 21.5 cm