8. Buoyed Weight: Suspended Drillpipe. A 700-ftlong steel pipe weighs 139lbf/ft (per length). The pipe outer and inner diameters are 7.5-in and 2.0-in, respectively. This pipe is to be suspended (completely immersed) in a vertical borehole (underground). Determine the "hookload" (force) required by the hook if the borehole (a) is empty (i.e., determine the "weight in the air") and (b) is filled with 12-ppg (lbm per gallon) clay-water mud (i.e., determine the "buoyed weight"). [1 gallon = 77/576ft3;1slug=32.174lbm;g=32.174ft/s2.] Ans. (a) 97,300lbf; (b) 79,393lbf