Question

How long is a pendulum with a period of 1.0 s on a planet with half the gravity of the earth?

Answer 1

@satellite73

Answer 2

@KeplJoey offers the following:

The formula relating period, length and gravity is given by

T = 2π√(L/g).

We want to find the length, so we need to solve for L. Dividing through by 2π, then squaring both sides, then multiplying through by g, results in

L = gT²/4π².

We're given that T = 1.0 s, and the gravity has half that on earth, or
g = 4.9 m/s².

Putting in this info gives

L = 0.124 m.

@Daniellelovee