A child wanders slowly down a circular staircase from the top of a tower. With x, y, z in feet and the origin at the base of the tower, her position t minutes from the start is given by (a) How tall is the tower? height= ft (b) When does the child reach the bottom? time= (c) What is her speed at time t? speed= minutes ft/min (d) What is her acceleration at time t? x=30 cost, y 30 sint, 90-5t. acceleration= ft/min?