Pendulum / Interrupted Pendulum


Related Applets:

Spring-Mass Oscillator (Kinematics)

Spring-Mass Oscillator (Energy Changes)

A Simple Harmonic Oscillator

Phase Difference


Drag the pendulum bob to one side and release.

The bob may (i) oscillate or (ii) undergo a complete or incomplete circular motion, depending on the level of release and whether or not the pendulum is interrupted by the pin.

Assumptions:

(1) All frictional forces are negligible.

(2) The string is inextensible.

(3) The radial velocity of the bob will disppaear instantly when the string becomes straight after a free fall.


No interruption: The bob oscillates to and fro. A graph showing its displacememt against time is traced and compared with the corresponding SHM graph.

The oscillation is simple harmonic only when the amplitude is small.

 

With pin-interruption: The subsequenct motion relies on which region(I, II or II) the bob is released.

 

Region at where the bob is released

I

No work is done on the bob by the tension, so the sum of kinetic energy and potential energy is always a constant.

II

This is a jumping pendulum.
II