The displacement (in metres) of a particle moving along a straight line at time t seconds is given by s(t)=t(4−t)sint for 0≤t≤4.
(i) Find the velocity v(t) of the particle.
(ii) Determine all values of t in the given interval (other than the endpoints) at which the particle is momentarily at rest.
(iii) Calculate the acceleration of the particle at t=π seconds.