DEFINITION OF MOMENT. 71 



.ilnnce each other and cannot separately maintain eqoi- 



~ 0, and O m o ; 



v ) v 



' + 

 These lead to the six coml 



ST. 



i A'.--/lr)-0, V -A>;-0. 



.il enunciation may be given of the last three 

 I by means of a new definition. For the take of 



us already cmr. 



a force with respect to a point. The moment 

 of a i!i iv-|M-, t to a i*>mt i* the product of the force 



iLir from the point on the direction of the 

 fae, 



ment of a force with respect to a plane. The 

 of a force with respect to a plane is the product of the (b 



t* application from the plane. 



incut of a force with respect to a *trai<jht line, Kenolve 

 ' respectively parallel and per- 

 : the pr \e component 



perpcmlionlar tlie shortest distance between 



the straight line nn i tin <lire . is component i* called 



the motif force with respe< >traight line. 



11 nt of a force with respect to a straight line 



is eoual to the moment of the compon< force pcrpen- 



straight i respect to the point at which 



ii this component perpendicular to the 



straight in..- meets the straight y Art *. the 



mom < force may be found lv taking the sum of the 



of any two forces into which the perpendicular 

 .iay be resolved. 

 .e force IB parallel to the given straight 



ai-lit line is y.er. If the force IS p*rp* 

 to the given straight line, its moment about the straight line 

 rcc into the shot test diatinee butwesn it 

 and the given straight 1; 



