EXAMPLES. 171 



85. Two equal circle* of radio* a are drawn, each passing 

 tin- centre 01 a third circle touch** 



me of their ; rsection for iu centra; 



iistance of the c< Tu\ity >f the smaller area in- 



d betwiv and inner circles from the common 



radius of the first two is 



*w-:i 



36. The density of a triangle vane* as the n u power of 

 nee from the base; determine n v centre of 



gravity of the triangle divides the straight line joinin 

 v with the middle point of the base in the ratio of ." 



: ie centre of praN volume formed by 



the ax in of x of die area of the < 



38. Fi iul the centre of gravity of the volume generated by 

 ition of the area in Ex. 27 round the axis of y. 



:ie centre of gravity of a hemisphere when the 

 - as the square of the distance 



40. Find the centre of gravity of the solid generated by 

 a semiparabola bounded by the latus rectum revolving round 

 itus root 



Rctvlt. Distance from foots - ft of latus rectum. 



solid included between the surfaces of a con- 

 as hyperbploid and its conical asymptote is cut by two 

 planes perpendicular to their common 1 the noV 



centre of gravity of that portion which lies between 

 planet. 



Jforaft. Midway between the plane*. 



