SI2 



DE FIGVRA 



co maius rpatiiim cxeretnr , quo maiorem valorem 



obtiiiuerit formula — jTip— H EoT^;"- Qiioa eniin 



ipfam fridionis quantitatem attinet , ea eft przffioni 

 mutuae proportionalis, quae preflio fuerit i:^ n , fri- 

 ^io certae cuipiam eius parti ^n aequabitur , cu- 

 ius diredio cum fit normalis ad OP, cr:t eius 

 momentum in rotam A~<^n(r-|-pcol.(p), in ro- 

 ram vero B:^(5^n(j--h^cof 4*),' quorum momen- 

 torum fumma eft — (5"n(r n-j-f-pcof (fj-f-^cof \l') 

 nziJrifcof 0). Vnde momentum \is rotam A cir- 

 cumagentis, quod ponimus -M debet efle Mz: n^fin.(|) 

 -i-(5TI(r-Hpcof(I)). 



8. His expoiitis perpendamus ipfum motuni 

 rotarum , et dum angulus <^ elemento d^ augetur , 

 Tideamus quantum angulus >) interea crefcat. Com- 

 modiffime hoc colligimus ex aequatione i-cof w— r+i' 

 -|-pcof.(|)H-^cof v{^, quas differcntiata dat 

 • f </wfin. oir: ^r-f-a^x+^ cof (P-;)^(t) fm.c^) -f fl'^ cof vj^-^^ v[/ fm. v[/ 

 at drzz — dpcoC^P et ds:=z~-dqco[.\\j \nde fit 



c^/ufin, u — p(/(f) fm. (p-l-^^ 4^ fin. \|/ 

 quare cum fit £"fin.w=:/)fm.(pH~^fin.\[/ erit 

 o — ((i(p — diii )p fin. (p -h [d-^ - dis^) q fin. \\f 



verum eft d(i\—d(^—d^ et d^\f — d'^—dy\y vnd© 

 fequitur : 



$d^im.(^=:qdy^(m.^ ideoque l^ -^. 

 r Anga- 



