/'and Q are two forces whose directions are at right 



angle*, si. the central axis from their 



lines of action are as /* t 



8. ces set on a rigid body and mnint 



in equilibrium, ' all in one 



A Will ! 



:u h"u- may IK about t 



app] 



Mg on a rigid body is c(\ 



> a single force : .-..v tlt:it it will also be .t t 



force alter the body has been turned through any 

 about the uxi* uf s, the direetiuiw of the forces remain - 

 :hc sam< 



E(r)-S(r)2cxj), 



and S hS(7)J / -2(r)2 v Ax+ ) 



ces act at the angular points of a tetrahedron in 



: the opposite faces, 

 to the areas of the faces in magiii: 

 cs have the property coni 



\v that no two sides of 



i arc paralK-1, thrro is but one point, at which force* 



ind pro; stances of 

 the point from them, can be in un. 



Two forces acting at a point are represented in magni- 



4 drawn from that } 

 r resultant is constair 



magnitude an 1 tlu l<>ctm of the u\ 



i lines which n-present the forces. 



8. If forces P, Q, R acting at the centre of a circular 

 ia along ii OA 9 OB, OCbee^i to foraes 



ug along tho sides /'' II of the inscribed 



. shew that 



7 *L*L*L n - K 



Hi' C.l 



