Angular frequency - w (omega)

1 When an object oscillates with simple harmonic motion, the frequency is given by one over the period, in cycles per second (Hertz)

Frequency ... f = 1/T ... cycles per second.

2 When a wheel rotates, the angular frequency is given by one over the period, in radians per second.

At once ...

... angular frequency ... w = 2p/T ... radians per second.

3 The projection of circular motion (the shadow cast on a wall by a distant light) is simple harmonic motion described by ...

y = A sin wt

... where w iis the angular frequency of the circular motion in radians per second.

Uniform circular motion, of frequency w iwith amplitude A, is called the reference circle for SHM.