- Three particles of masses \(3 m , m\) and \(2 m\) are positioned at the points with coordinates \(( a , 8 ) , ( - 4,0 )\) and \(( 5 , - 2 )\) respectively.
Given that the centre of mass of the three particles is at the point with coordinates \(( k , 2 k )\), where \(k\) is a constant, find the value of \(a\).
(5)