The displacement time graph of a particle executing S.H.M. is shown in Fig. 14.5. Which of the following statement is/are true?
(a) The force is zero at t = 3T/4.
(b) The acceleration is maximum at t 4T/4.
(c) The velocity is maximum at t = T/4.
(d) The P.E. is equal to K.E. of oscillation at t = T/2.