Question

Pontoon bridges use buoyant forces to support loads. This problem will ask you to consider a 10 ft section of the pontoon bridge sketched below. The bridge deck is 4

ft wide, and each 10 ft section has five 55 gallon drums on each side. Each drum has a diameter of 22 in, so the cross-sectional area of each drum is 2.64 ft^2, and each drum is 2.79 ft tall. Assume the bridge deck and the bracing system for the drums weigh 2300 lb per 10 ft section but occupy negligible volume. The bridge floats in water with y = 62.3 lb/ft³. Part A What is the cross-sectional area of all ten drums? [ft^2] Part B What is the volume of all ten drums? [ft^3] Part C When the bridge is unloaded, what length of the drums will be underwater? [ft] Part D How much weight can each 10 ft section carry without sinking? [lb]

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