Simple Harmonic Motion Simple Harmonic Motion SHM SHM

Simple Harmonic Motion

Simple Harmonic Motion (SHM) • SHM: is periodic motion about an equilibrium point where the restoring force is proportional to the distance from equilibrium – Periodic motion: Repeated motion – Equilibrium position: Position where object will come to rest. Fnet = 0

Amplitude: maximum displacement from equilibrium – Relates to the amount of energy – Unit: meters

Simple Harmonic Motion ex: pendulum (at small angles) and mass on a spring

At equilibrium • Velocity is at a maximum • Net force is zero At maximum amplitude • Velocity is zero • Net force is at a maximum When would the acceleration be zero? When would it be a maximum?

Why will the mass eventually stop? Friction

What can you tell me about the: • • Force at B? Velocity at B? Acceleration at A? Speed at C?

2 Truths and a Lie With a partner 1. Write down 2 2. Write down 2 truths and 1 lie about the velocity about the force of of an object in simple harmonic motion. You must use the words equilibrium and maximum amplitude in your statements.

Period & Frequency • Period (T): time it takes to complete one cycle – Unit: seconds • Frequency (f): number of cycles or vibrations per unit of time – Unit: 1/sec = Hertz (Hz)

Practice Problem An angry bird flaps its wings every 1. 2 seconds. What is the period and frequency of the wings’ motion?

SHM and Waves • Simple Harmonic Motion- Pendulum Waves