Masses of `2 kg` each are placed at the corners `B` and `A` of a rectangular plate `ABCD` as shown in the figure. A mass of `8 kg` has to be placed on the plate so that the centre of mass of the system should be the centre `O`. Then the mass should be placed at :
.

Options

A. `1 m` from O on` OE`
B. `2 m` from O on OF
C. `2 m` from O on OG
D. `2 m` from O on OH

Answer

A

Explanation

(a) `x_(cm) = (m_1 x_1 + m_2 x_2 + m_3 x_3)/(m_1 + m_2 + m_3)`
` rArr 0 = (2(-2)+(-2)+8 x_3)/(2 + 2 + 8)`
`rArr x_3 = 1 m`.
.