24. A particle moves according to the displacement function s(t) = 2t^3-15t^2 + 10t + 1, where s(t) is measured in centimeters and t is measured in seconds. a) What is the initial position of the particle? b) In what direction is the particle moving at 2 seconds? What is its velocity and acceleration? c) When does the particle change directions? d) When is the particle neither accelerating nor decelerating?