The overturning moments are given by Equation 7-78 as, 



ft.-lbs. 

 Mm = R^dc = 16,900(7.5) = 126,800 — -~ , (T = 6 sec.) 



It. 



and 



ft.-lbs. 

 M^ = 86,300 —: — . (T = 10 sec) 



For the example, the total forces, including the hydrostatic force 

 from Equations 7-80 and 7-81, 



8.4\2 

 64 7.5 + - 



R, = 16,900 + ^ '— = 16,900 + 4,380 = 21,280 Ibs./ft. 



say 



R^ = 21,300 Ibs./ft. (T = 6 sec.) 



R, = 16,400 Ibs./ft. (T = 10 sec.) 



Then 



t m s 



8.4p 



6417.5 + 

 M^ = 126,800 + '- = 126,800 + 17,100 , 



Ib.-ft. 

 M^ = 143,900 -^ , (T = 6 sec.) 



say 



Ib.-ft. 

 M, = 144,000 — — 

 ^ ft. 



and 



ft.-lb. 

 M^ = 106,600 -z— ■ (T = 10 sec.) 



7-151 



