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 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 Write down 2 truths and 1 lie about the velocity of an object in simple harmonic motion. Write down 2 truths and 1 lie about the force 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