CH. IX CENTRIFUGAL FORCE I 39 



ward ; A is the point at which the outside wheel 

 rests on the around. The centrifugal force tends 

 to turn the weight about the point A, and in so 

 doing it is resisted by the weight at G, which acts 

 with a leverage AB. 



As the coach tips more, and AG becomes more 

 nearly vertical, the leverage AB decreases, and the 

 action of the weight to resist the centrifugal force 

 becomes less, until when G is over A, the weight has 

 no leverage and the coach is acted upon by C only. 



It is evident that, the centrifugal force and the 

 weight being constant, the effect of the centrifugal 

 force will depend entirely upon the height of G 

 above the ground. It is also evident that, from the 

 moment the wheel which is on the inside of the 

 curve, leaves the ground from the action of the 

 centrifugal force, the resistance of the weight to 

 overturning, diminishes. 



With a known weight of coach, the centrifugal 

 force, corresponding to any speed round a turn of 

 any radius, may be computed. The formula for 

 this computation is as follows : — 



centrifugal force = — ; where 



O 1.1.1 } 



w = weight in pounds. 



v = velocity in feet per second. 



r = radius of curve, in feet. 



The quantity 32.2, usually expressed by g, is the 

 velocity in feet per second that a falling body has 

 at the end of the first second of its fall. 



