Q: A particle P starts from rest with constant angular acceleration α in anti-clockwise direction from point P on a circular path of radius R . the acceleration of the particle at t = √(π/α ) is
(a) $ R \alpha \hat{i} + \pi R \alpha \hat{j} $
(b) $ R \alpha \hat{k} + \pi R \alpha \hat{j} $
(c) $ – R \alpha \hat{i} – \pi R \alpha \hat{j} $
(d) None of these
Ans: (c)