The phase difference between the instantaneous velocity and acceleration of a particle executing sim

Question

The phase difference between the instantaneous velocity and acceleration of a particle executing simple harmonic motion is\

Professor PC Thomas Classes · Answer

(d) : Let $y=A \sin \omega t$ 
$ \frac{d y}{d t}=A \omega \cos \omega t=A \omega \sin \left(\omega t+\frac{\pi}{2}ight) $ 
Acceleration $=-A \omega^{2} \sin \omega t$\ The phase difference between acceleration and velocity is $\pi / 2$.\