A heavy rope, 60 ft long, weighs 0.7 lb/ft and hangs over the edge of a building 130 ft high. (let x be the distance in feet below the top of the building. enter xi* as xi.) (a) how much work w is done in pulling the rope to the top of the building? show how to approximate the required work by a riemann sum. lim n n 7xi??? 10??? correct: your answer is correct. ??x i = 1 express the work as an integral. 60 correct: your answer is correct. 0 7x 10??? correct: your answer is correct. dx evaluate the integral. 42 incorrect: your answer is incorrect. ft-lb (b) how much work w is done in pulling half the rope to the top of the building? show how to approximate the required work by a riemann sum. lim n n 7xi??? 10???+ changed: your submitted answer was incorrect. your current answer has not been submitted. ??x i = 1 express the work as an integral. 30 correct: your answer is correct. 0 dx evaluate the integral. ft-lb