\ of Central Forces. 4it 
Tf it “be required’ to exterminate m, we have 
y? 1? ov aa 
- xX— = —+— (Propofition I.) or 
5 r 
pin aaa se 2m At 
v* = 5? 1X (Fe =) = SST 
r oa ial hah m—1 Xr 
‘ cAtt 
and, by this Propofition, B?7++ == meer there- 
—— 2m 
fore s* & 1-¢ = » 01m = 
as Gorhie : 
sox nm—1 X 1+cec_ Ss? K 1c 
2 pa e 
wherefore, by fubftituting this value in the above 
equation, we have y* +-r pod ae Mining r? y 
¢ 
2 eee nD fae 
S 1—c Q rpy 
oped LEX pte 9, yg othe Ti 
c or ee Y Vy? —p’? 
MRM KT I eiok Lahybi 
y Vey —2e—om XP bar y—oMr 
SYi—ex ry 
IV cy 2s? K Ie XY her ys K-94; 
if the fluent therefore be taken, when y = the 
diftance of the other apfe from the centre, the 
arc defcribed in pafling from one apfe to ano- 
Beez ther, 
