Brard 
ut) #, .204')] -|-» (Pato (mM) Hy, 
— 0% r “(M) oy dy my) (7.22) 
- -FUt je 3 (6) ® 5(M,) a2] 
Putting 
es oe [a s roe 
eee. 
- 
» 
T 
eta! 
> 
Ka 
we see that the final expression for the system of hydrodynamic 
forces exerted on the body is as follows 
a ee 
is the ''quasi-steady''system of forces and BA is that due to 
(7.23). 
qs. 
the so cailed ''added masses". 
vase b- 
This case is a limiting one, involving the assumption that the 
motion of translation of the body became uniform ata time t consi- 
derably anterior to the present time t,. Since 2 = 0, one has 
(7. 24) 
b 
q cannot reduce to a torque because of the effect of 
But 
the free vortex sheet. 
1240 
