TRACT 27 . PLACE OF GREATEST ATTRACTION.
73
of
By Art. 4, the attraction
C * i ■, PF + PC ,
V PFCG IS 5 , PG X II. J. - ~ SX X I)
) PG
PGAH IS S
, , PH + pA n i ft
PG X h. 1.- — sx x ii. 1. —
PG
1 “g-te + W }
ax 3 f
. ]. —. C
a J
By Art. 5 , the attraction of efc is
EF . FC . PE
-- X (PC — PE —
EO ' 1 ^
EF , , FC ! +EC . l'C + l'E. tF SC
- X h.I.-=~ X
EC TE . EC + FF. . EF CS
[qq -g(a-.r) — gc x h.I.
a eg + eqq + aax— hex-
]•
g . (c+e) . (a— x) ■
Lastly, by Art. 6, the attraction of bde is
x (pb — PE
x h.
BE 2 + BE . BP*— PE . PEPE . BE—PE . DE
) *
(a — x) x (d — g + - x h. 1. - c + de
-eg.
eg
These quantities being collected together, with their pro-per signs, and contracted, we have ,
i X
ab . ad—qq-
-V C . -
’a ee
| cc g.{a-x) ^ j (cej
-itx - , . ag+qq — bz
-h x x hyp. log. — + j
de-
(i b+d) x- eg) . (otg + eqq + am — bex)
SS • (cc-cc) . (a-.*)
for the whole attraction in the direction fe.
9. Having now obtained a general formula for the mea-sure of the attraction, in any sort of triangle, if the parti-cular values of the letters be substituted, which any practi-cal case may require, and the fluxion of this attraction beput = 0, the root of the resulting equation will be the re-quired height, from the bottom of the hill.
10. But for a more particular solution in simpler terms,let us suppose the triangle abc to be isosceles, in which casewe shall have d=e, and g ~2l) ~ 2c, and then the above ge-neral formula will become
Qad—qq—dx
s X
+ t ?.2i>xh.l.
dd
X
&
b -f x x h. 1
2 ab + qq — bx
{b+d) . x2d6 a 4 dq^~~ (fe 2 —a 2 )26* . (a— x)
for the value of the attraction in the case of the isoscelestriangle, where f is = </ - A-ab'x + d'x-). And the
fluxion of this expression being equated to 0, the equation