EQI M OF PAKAM.rt. Foam. 



twins a simila M, an<l the whole yt<-m will be 



to A fom : , ami 



t 



- body from the axU of * to the axit 

 ofy. 



" /IK/ fJU ttWi'/Kmj or" "fin'liMitm f a tytttm 

 parallel fire** acting on a rtyiVf Wy til o 



\ -f |nral!.-l f<rci can be reduce! ingle 



force and a conplc. If neither of the** vnnUh r^uililirinm 

 i tine a dingle force cannot neutral ixr a covpla 

 ! ! alone vaninh rnuilibri'; 



iropoasible, becanae there renmin an unVaUnr. 

 the couple alone van < impoMible, Wtf 



equilibrium 



neoeaaary that both the force and the couple should 

 vanish; that is 



-0 an! 



reluct of a force into the perpendicular drawn 

 m any called the moment of 



ive just been obtained may be thtu 



A i ! forfeit a r ting on a rignl Wy fm aM 



'nttm ifth* mm oftkfrrc* g&*e>. 

 'h* turn of the moment* of the fircet nmurf oa flhy/n /n 

 the plane also wnisht*. 



Conversely, if the forces are in equilibria -um mot 



vani- ^um of their moments round any origin 



in the plane. 



sum must be understood aMmiV ' 



t in tho opposite direction must be considered 

 ^o mom<- : conidered poftlir* when the cor- 



^gp, -he Imly in w dirccttos). 



.red tugati* when the LuiieapoMinf 



couples tend to turn the body in the qapotift direction. 



