Dear student,
A simple pendulum consists of a heavy point mass body suspended from a fixed support through a weightless inextensible and perfectly flexible string so that it can oscillate freely. Simple pendulum is an idealised model that can not be achieved in practise because we can not have a point mass and weightless string in practise. The only forces that act on the mass are gravitational force and tension of the string.
Law of Length: The time period of the simple pendulum is directly proportional to the square root of its length. This property is known as the law of length. Law of Iscochronism: The time period of the simple pendulum is independent of the amplitude, provided the amplitude is sufficiently small.
Regards