Problem # 7: A chain lying on the ground is 11 ft long and weighs 100 lbs. How much work is required to raise one end of the chain to a height of 9ft? \fProblem #8: Suppose that the temperature of a cup of coffee t minutes after it is poured is given by T(t) = 21 + 70elk, where k = Find the average temperature of the coffee during the first 39 minutes after it is poured.Problem #5: Find an integral which represents the volume of the solid obtained by rotating the region enclosed by the curves y = x and y = 4x + 77 about the x-axis. . 11 .11 (A) n [x4 - (4x + 77)2] dx (B) - n (4x + 77 - x2) dx ( C) . [x4 - (4x + 77)2] dx 11 11 - -11 n (x2 - 4x - 77)2 dx (E) . [(4x + 77)2 - x4] dx (F) |1 (x2 - 4x - 77)2 dx (G) n [(4x + 77)2 - x4] dx (HD) [ It (4x + 77 - x2)2 dx -11 11Problem #3: Which of the following represents the area of the region enclosed by the curves y = x and y = 4x + 77 for -8