What is the length of a simple pendulum that marks seconds by completing a full swing from left to right and then back again every 2.0s?

explain plz

2 answers

i know u use this formula T=2pi(L/g)^1/2
but i'm not getting the right answer
That is the correct formula
2 = 2 pi (L/g)^1/2
4 = 4 pi^2 (L/g)
L/g = 1/pi^2
L = 9.8/9.87 = 0.99 m