Question

A pendulum makes 120 complete oscillations in 3.00 minutes at a location where g= 9.98m/s^2

Find the period of the period
Find the length


I tried using the 2pi sqrt. L/g formula

I don't know why I got this huge number

Answer 1

The period P is 3/120 = 1/40 minute = 1.5 seconds.

P = 2*pi*sqrt(L/g) = 1.5 s
sqrt(L/g) = 0.2387
L/g = 0.05699
L = 0.569 m

That doesn't seem very huge to me.

Answer 2

Where did you derive 0.2387 ?