During one oscillation, a particle performing SHM covers a total distance equal to 4A, where A is the amplitude of SHM. The time taken to cover this distance is the period (T) of SHM.
Average speed = \(\frac{distance\,covered\,in\,one\,oscillation}{time\,taken\,for\,one\,oscillation}\)
\(\therefore\)vav = \(\frac{4A}T\)
But T = \(\frac{2\pi}{\omega}\)
Where \(\omega\) is a constant related to the system.
\(\therefore\)vav = = 4A x \(\frac{\omega}{2\pi}\) = \(\frac{2\omega A}{\pi}\)
But \(\omega\)A = maximum speed
\(\therefore\) Average speed = \(\frac{2}{\pi}\) x maximum speed