Diagram for Motion of Simple Pendulum as S.H.M.- Smarter Techniques

 

How to draw a vector diagram for the motion of Simple Pendulum as a Simple Harmonic Motion ? (Smarter Techniques)

    Students often find it confusing to represent the forces acting on a pendulum. Let’s break it down into simple, visual steps.A simple pendulum is a heavy particle tied at the free end of a long suspended string at the support. But in practice, instead of a heavy particle, a heavy bob is attached.  The length of the pendulum is the distance between the point of support and the centre of the bob.  The bob oscillates and performs Simple Harmonic Motion (S.H.M.). Fig. A represents an oscillating simple pendulum.

Fig A

Consider Bob of mass m is attached to a string of length L and is oscillating between A and C. Let the pendulum be at an angle Ө from vertical.

   The weight mg is resolved into two components: mgcosӨ as the ǁ component and mgsinӨ as the ⏊ component.

mgcosӨ is balanced by tension in the string, and mgsinӨ acts as a restoring force to bring the bob to mean position B.

As Ө is small,

 sinӨ = Ө = x/l.

Restoring force

 F = -mgx / l,

∴  F  ⍺ - x

The restoring force is directly proportional to displacement and opposite to it.

This is Simple Harmonic Motion  of a simple pendulum.

Thus, the motion of a simple pendulum is linear simple harmonic motion.

How to Draw Diagrams in Physics  by Smarter Techniques,

 I have already discussed general guidelines for drawing diagrams on A4 sheets in a previous article.

So do you want to know 'How to draw a vector diagram for the motion of Simple Pendulum as a Simple Harmonic Motion ' using the given guidelines?

Let us learn with the help of the following video the actual smarter method of drawing the diagram.