Problem 2: 2Pi

Problem 18: 256Pi/3

Problem 28: 332Pi

Problem 12: 525 ft/lb

Problem 14: 3200 ft/lb

Problem 16: 108,000Pi ft/lb

Problem 4: 14/9

Problem 6: (4/Pi)(sqrt(2)-1)

Problem 8: 3/14

Problem 14: (3 ± sqrt(5))/2 (both roots are answers)