The angular speed ω of an object moving in a circle is the angle it turns through per second: ω = Δθ/Δt. The unit is rad s-1.In one complete revolution the object turns through 2π radians in one time period T, so ω = 2π/T = 2πf, where f is the frequency of rotation.Angular speed is linked to linear speed by v = ωr, where r is the radius of the circle.Every point on a rotating rigid object has the same angular speed, but points further from the centre have a greater linear speed. For example, a wheel turning 5 times per second has ω = 10π rad s-1 at every point.