1) The motion of a ball is modelled by the functions x(t) = 4t, y(t) = -4.9t2 + 20t + 2 Where x(t) is the horizontal distance and y(t) is the height above the ground (both in meters) and t is time in seconds. a) What is the initial velocity of the ball? Write your answer in vector notation. b) Compute the maximum height of the ball. C) Compute the time when the ball hits the ground and the horizontal distance from its starting point when it hits the ground. d) Interpret dzy d2 x dt2 and dt2