# Formula Undamped Harmonic Oscillator Acceleration    Amplitude    Time    Angular frequency    Phase

## Acceleration

Unit
Acceleration of the harmonic oscillator at the time $$t$$. This can be, for example, the acceleration of the oscillating mass hanging on a spring.

## Amplitude

Unit
Maximum deflection of a harmonic oscillator. In the case of a spring pendulum, it is the maximum distance of the mass from the rest position of the spring (undeflected mass).

## Time

Unit
Time at which the acceleration is $$a(t)$$.

## Angular frequency

Unit
Angular frequency $$\omega = 2\pi\,f$$ describes how fast the harmonic oscillator oscillates.

## Phase

Unit
Phase is an angular quantity that determines what acceleration $$a(0)$$ the harmonic oscillator had at time $$t=0$$:$$a(0) ~=~ -\omega^2\,A\,\cos(\varphi)$$