Vibratory motion is a type of motion in which a particle moves to and fro about a fixed point. It occurs at a fixed point as an object moves back and forth. It can also be defined as an object forced to move to and fro periodically, occurring when a particle is vibrated.
Task: Tie a stone at one end of a thread and hang it from one side of a table as shown in the figure. Pull the stone to a short distance from any side and release it gently. The stone will first go back to the initial position, from there, it will move in the opposite direction. After going to a short distance it will again return to the initial position and will go to the direction in which it was pulled. In this way, the stone will move in both the directions from its initial position.
This vibration is the to and fro periodic motion of the initial position (Fig.). This motion of the stone is called oscillatory or vibratory motion.
Hence, the vibratory or oscillatory motion is the motion, when an object is in to and fro periodic motion of its position. The motion of wall-clock’s pendulum is oscillatory motion.