### Simple Harmonic motion – an introduction

Simple Harmonic Motion, usually shortened to SHM is a description of the way most structures vibrate. When elastic materials vibrate or oscillate they almost always move back and forth around a centre point. The force needed to push them away from this centre point is directly proportional to how far they are pushed. This is SHM.

All manufactured engineering structures are likely to be subject to vibration or oscillations. That includes buildings, buses and cars, ships and bridges. That oscillation can be annoying and sometimes dangerous or destructive, threatening the whole integrity of the structure. In this lesson I aim to define and explain simple harmonic motion showing common and understandable examples.

### Simple harmonic motion of a spring

This video lesson below explains the example of a weight oscillating on the end of a spring, an example most often used in physics examination questions. The video includes a run through a sample calculation.

SHM notes are here