Simple harmonic motion can be derived from Newton's second law and Hooke's law. It has an equation of motion described by this acceleration function:
The force acting on a particle (and hence, the acceleration) is proportional to the distance of a particle from its equilibrium and is directed towards the equilibrium point. It is a restoring force always trying put the particle back in equilibrium.
- The constant is the angular frequency (). It is related to the mass (constant) and stiffness of the spring (constant). Increasing will produce quicker oscillations.
- The constant is the phase angle; it describes where in the cycle the oscillations begin. means the particle starts at rest from maximum displacement. Different values of mean a non zero initial velocity closer to the equilibrium point.
- The amplitude is the maximum height of the oscillations measured from equilibrium.
- The magnitude and direction of the position, velocity and acceleration vectors are show for comparison.