41 Cistern Program

[Gerson W. Barbosa]

(08-13-2016 11:06 AM)Werner Wrote:  Or (in radians, L, R, H on stack):

Code:

\<<
  \-> L R H
  \<<
    1 H R / - ACOS DUP +
    DUP SIN - L * R SQ * 2 /
  \>>
\>>

stack only:

Code:

\<<
  OVER / 1 SWAP - ACOS DUP +
  DUP SIN - SWAP SQ * * 2 /
\>>

Or, without SIN:

Code:


«  L R H
  « 'L*(SQ(R)*ACOS(1-H/R)+(H-R)*√(H*(2*R-H)))' EVAL
  »
»

Regards,

Gerson.

P.S.: That's essentially the same formula provided by Wojtek. I hadn't seen the attachment, instead I used one I had derived years ago when solving a perhaps more interesing problem ( Time to drain a horizontal cylindrical tank ).