Fig 7-5 By building a Cartesian coordinate, position of y point c is found at m11+m C C cn (7-1) m1+m2 or written as mx,+.x cm m1+m2 A (7-2) m,y1+m2y B m1+m2Fig 7-5 m1 m2 1 r  x y O 1 2 1 1 2 2 m m m r m r rcm + + =    1 2 1 1 2 2 m m m x m x xcm + + = 1 2 1 1 2 2 m m m y m y ycm + + = cm r  2 r  ' cm r  C C’ By building a Cartesian coordinate, position of point c is found at : (7-2) (7-1) or written as:  m1 m2 A B C