The period T of a pendulum is given by:
where L is the length of the pendulum while
is the gravitational acceleration.
In the pendulum of the problem, one complete vibration takes exactly 0.200 s, this means its period is
. Using this data, we can solve the previous formula to find L:
where L is the length of the pendulum while
In the pendulum of the problem, one complete vibration takes exactly 0.200 s, this means its period is