# Homework Help: Pendulum Lab HELP

1. Dec 28, 2004

### sinthon123

I am doing a lab report that proves the formula for the period of a pendulum. One part of the assignment requires that I explain how the pendulum goes from UCM (Uniform Circuluar Motion) to SHM (Simple Harmonic Motion). I have described the transition as follows:

"Uniform circular motion requires an object to be moving at a constant speed with a constant radius. The pendulum displays UCM with its constant speed and constant string length. The pendulum is accelerating constantly in UCM because it changes direction. Velocity is changed, and a change in velocity over a period of time creates the acceleration. So therefore, by graphing acceleration on the y-axis and time on the x-axis a characteristic SHM (Simple Harmonic Motion) sinusoidal graph will appear."​

I don't know if I have described the highlighted part correctly... Is it the acceleration that will be graphed or the velocity (since it changes)... The goal here is to show that, using a graph, the characteristic sin graph will be shown. I dont know if graphing my acceleration on the y-axis is going to cause the sin graph to appear. Thank you very much for helping.

Last edited: Dec 28, 2004
2. Dec 28, 2004

### \$id

Well for SHM
displacement, velocity and acceleration will vary sinusodically with time. It will not matter which one you plot if all you need is a sinusodial graph. Whether you get a sine or a cosine wave will depend on how you took the data,