

SCREW WITH FRICTION. 



/' A 1- 



b tan a 



a 1 + /*tana 



-tan*. 



>sc P about to prevail over W 9 we shall find 



.similarly 



LAMPU 



rcctangolar prism, whoso breadth i* 2.8:5 feet and 

 nets less , is laid with its axis horizontal, 



i its smaller face on an inclined plane tv 

 cocrTi M fa. Shew th:r >n of 



the plane is gradually increased, the prism will roll before it 



roughness of a plane \vhuli is inclined t 

 horizon at a known angle bo such that a body will just 

 rest supported on it, find the least force requisite to draw 

 vxly up. 



Results. Let a be the inclination of the plane, W the w- 

 of th.- i<" . . and it acU at an 



inclination a to the plane. 



8. Two rough bodies rest on an im-lim><l plane, and are 



which is narallol to the plane ; if the 



coefli be not trie same for both, find the 



greatest inclination of the plane which is consistent with equi- 



ira. 



