1421 OUTLINES OF NATURAL PHILOSOPHY. 



collected in the centre of gyration. The question 

 wxmld then be reduced to the simplest case of 

 211. where the system consists only of two bo- 

 dies. The preceding solution is, however, more 

 direct. 



2.23. If in the two preceding cases, W and F be 

 both supposed to be sustained by the axis when 

 the whole is at rest ; the part of the weight of P 

 of which the axis is relieved when the motion be- 

 gins, is to the whole weight of F, as the Force by 

 which it is accelerated to the force of gravity. 



Thus, in the instance of the sphere, the pressure on 

 the axis is diminished by the quantity 



If W=3001b., F = 10 Ib. ; - ?~ - = \,so that 



F+ iW 



the diminution of pressure is 2 Ib., and therefore 

 the whole pressure, when the motion takes place, 

 is 308 Ib. 



If it were required to find directly the part of F 

 pressing on the axis, it will come out 



W 



= - 4 - X F, which, in the last example, 



15 



would amount to 8 Ib. 



ATWOOD on Rectilinear and Rotatory Motion, 6. 

 p. 183., &c. FRJSII Mechanica, Opera, torn. u. 



p. 133., 



