The time period of a simple pendulum is the time it takes for the pendulum to swing back and forth once. The time period of a simple pendulum is constant because it is determined by the length of the pendulum and the acceleration due to gravity.
The length of the pendulum (the distance from the pivot point to the center of mass of the pendulum bob) and the acceleration due to gravity are both constants, so the time period of the pendulum remains constant as well.
The time period of a simple pendulum can be calculated using the following formula:
T = 2π √ (L / g)
where T is the time period, L is the length of the pendulum, and g is the acceleration due to gravity.
The length of the pendulum and the acceleration due to gravity are both constants, so the time period of the pendulum remains constant as well.