1. Oscillations – motions that repeat themselves Period ( T ) – the time for one complete oscillation Frequency ( f ) – the number of oscillations completed each unit of time Units: 1 Hertz ( Hz ) = 1 oscillation per second

2. Consider the forces acting on the mass when it is at rest. Equilibrium Position – Occurs when the net force acting upon an oscillating object is zero. Net force acting on a mass on a spring

3. Simple Harmonic Motion – the motion executed by a particle of mass m subject to a force that is proportional to the displacement of the particle but opposite in sign. Restoring Force – A force that acts towards the equilibrium position and results in oscillatory motion. Hooke’s Law

4. Consider an object moving with uniform circular motion In rotational terms, the object moves with a constant angular velocity ω and therefore angular position θ is given by

5. Consider the projection of the motion of this object onto the horizontal plane. This motion appears exactly like that of a mass on the end of a spring!

6. But Simple harmonic motion is the projection of uniform circular motion on a diameter of the circle in which the circular motion occurs

7. Amplitude ( x m ) – the magnitude of the maximum displacement from the equilibrium position

8. Oscillations Simple Harmonic Motion – the motion executed by a particle of mass m subject to a force that is proportional to the displacement of the particle but opposite in sign. – periodic motion in which the position is a sinusoidal function of time Mass on a spring

9. Oscillations Angular Frequency In rotation, ω refers to the angular velocity. However, in oscillatory motion, ω is called Angular Frequency (ω) – rate of change of angular displacement of an oscillating object For one complete oscillation