Answer:
Length of the string that is tied to the pendulum
Explanation:
Galileo Galilei was the first scientist to contribute the pendulum theory, and according to this theory, the pendulum moves back and forth in a continuous process, under the influence of gravity and thereby attains the momentum. This pendulum is hanged at one end with a string, and is allowed to move back and forth by applying a little force.
The time taken by the pendulum in order to complete one cycle is directly dependent on the length of the string.