(1 point) A child wanders slowly down a circular staircase from the top of a tower. With c, 1, z in feet and the origin at the base of the tower, her position t minutes from the start is given by r = 25 cost, y = 25 sint, z = 70 - 5t. (a) How tall is the tower? height = ft (b) When does the child reach the bottom? time = minutes (c) What is her speed at time t? speed = ft/min (d) What is her acceleration at time ? acceleration = ft/min Note: The answer should be a vector, Input, for example, "" or equivalently "i - 2j + 3k"