Three particles of masses `m`,`m` and `4kg` are kept at a verticals of triangle `ABC`. Coordinates of `A`, `B` and `C` are `(1,2)` , `(3,2)` and `(-2,-2)` respectively such that the centre of mass lies at origin. Find the value of mass `m`.
Hint. `x_(cm)=(sum_(i-1)^(3)m_(i)x_(i))/(sum_(i=1)^(3)m_(i))`, `y_(cm)=(sum_(i=1)^(3)m_(i)y_(i))/(sum_(i=1)^(3)m_(i))`

Explanation

`x_(cm)=(m+3m-8)/(2m+4)=0`
`rArr 4m-8=0`
`rArr 4m = 8`
`rArr m = 2 kg`
Hint : `x_(cm)=(sum_(f=1)^(3)m_(i),X_(i))/(sum_(f=1)^(3)m_(i)), y_(cm)=(sum_(i=1)^(3)m_(i)y_(1))/(sum_(i=1)^(3)m_(i))`