Bodies ajfe6ied hy Fridlion, i8'i>' 



city generated by fridion will alio be the fame, to which if wc 

 add the velocity about the center at the beginning of the mo- 

 tion, we fhall have the whole rotatory motion ; hence there- 



ra ~~' - — __- 



fore, v + — X a — \/ a — 2F2; = ^a^ — 2F2, confequently 



«* X as^— V Xrs + ^x ri 



2F X <3i 



comes uniform. 



the fpace defcribed before the motion be- 



2. If this value of z be fubftituted into the expreffion for the 

 velocity, we fhall have ~ for the velocity when the 



fri£tlon ceafes. 



3. \i v-z=:a, then 2s no, and hence the body will continue to 

 move uniformly with the firft velocity. 



4. If V be greater than a^ then the rotatory motion of the 

 point a on the plane being greater than its progreflive motion 

 and in a contrary direction, the abfolute motion of the point 

 a upon the plane will be in the direction ML, and confequently 

 fridtion will now ad in the diredion LM in which the body 

 moves, and therefore will accelerate \.\\& progrejjive and retard 

 the rotatory motion ; hence it appears, that the progrejjive mo-- 

 ilon of a body may b accelerated by fribtion. Now to deter- 

 mine the fpace defcribed before the motion becomes uniform, we 

 may obferve, that as the progrellive motion of the body is now 

 accelerated, the velocity after it has defcribed any fpace % will 

 be —s/a 4- 2F2;, hence the velocity acquired = s/a + z¥% - ^^ . 



and confequently the rotatory velocity deflroyed — x 



■ ' ' y (I — . . - ■ 



^fl^-fzFz — ^, hence v y^ s/a' -\-^^%- a — ^a' ■^■q.Yz.^ 



—a 



therefore % tz — = ^ the Ipace required, 



,5; if 



