(21) Consider a rope described by the curve a: 2 at, y 2 (1152/2, z 2 (5153/3), where t 6 [0,1]. What is the mass of the rope if the density at each point is 6 = 1/ 2y/ a. (b) Find the length of the curve described by y = aarcsin(m/a),z = {fln (), between the points (0, 0: 0) and ($0,310, 20)