The Time It Takes for One Complete Swing of a Pendulum

Short Answer

The time it takes for one complete swing of a pendulum is called the period of its motion. The period T (in seconds) of a swinging pendulum is found using the formula seconds where L is the length of the pendulum in feet and 32 is the acceleration of gravity in feet per second.
Find the length of a pendulum whose period is 2.421 seconds. (Express the answer in feet and inches to the nearest inch.)