9. [Maximum mark: 17] An object moves along a straight line. Its velocity, vms, at time t seconds is given by v (1) = 1 + 771 - 21 +6, for 0 14. The object first comes to rest at t = k. The graph of v is shown in the following diagram. V At = 0, the object is at the origin. (a) Find the displacement of the object from the origin at 1 = 1. [5] (b) Find an expression for the acceleration of the object. [2] (c) Hence, find the greatest speed reached by the object before it comes to rest. [5] (d) Find the greatest speed reached by the object for 0 14. [2] (e) Write down an expression that represents the distance travelled by the object while its speed is increasing. Do not evaluate the expression. [3]