Answer:
Forward stroke area A = 0.25π(75)2 = 4418 mm2
Reverse stroke area A = 4418 – 0.25π(14)2 = 4264 mm2
(a) Forward stroke v = 200,000 / 4418 = 45.3 mm/sec
F = 5(4418) = 22,090 N
(b) Reverse stroke v = 200,000 / 4264 = 46.9 mm/sec
F = 5(4264) = 21,320 N