Learning Introductory Physics with Activities

The next situation to which you will apply and adapt your physics model is oscillatory motion: any back-and-forth motion that regularly repeats in time.

Oscillatory motion occurs when an object is displaced away from a stable equilibrium such that a net force acts to return the object to this resting position. The forces that lead to oscillatory motion are typically called restoring forces. A restoring force always acts against an object’s displacement from equilibrium to bring the system back to that equilibrium. Hooke’s Law, in which the force is directly proportional to displacement, is the canonical example restoring force.

Often, oscillatory motion can be represented by a position that is a sinusoidal function of time. This most fundamental oscillatory motion, simple harmonic motion, can be described by a sine or cosine function. More complicated oscillatory motion can be described either as a sum of sinusoidal functions or as a sinusoidal function multiplied by other functions such as exponential functions.