I. At time / =0, a small stone is thrown vertically upwards with speed 14. / ms from a prim. At time / = 7 seconds, the stone passes through A, moving downwards. The stone is modelled as a particle moving freely under gravity throughout its motion Using the model, (a) find the value of T. (b) find the total distance travelled by the stone in the first 4 seconds of its motion (c) State one refinement that could be made to the model, apart from air resistance, that would make the model more realistic. a)