Question

Masses 8, 2, 4, 2 kg are placed at the corners A, B, C, D respectively of a square ABCD of diagonal $80cm$. The distance of center of mass from A is:

• A. 20 cm
• B. 30cm
• C. 40cm
• D. 60cm

Answer 1

The correct option is B 30cm

Center of mass is given by=

$\frac{(m_1{x}_1+m_2{x}_2+m_3{x}_3+m_4{x}_4)}{m_1+m_2+m_3+m_4}$

The diagonal of a square is 0.8 meters

therefore using pythagoras law each side is of a distance 0.56 meters

So centre of mass

$\frac{8\times 0\times 2\times 0.56+9\times 0.8+2\times 0.56}{8+2+4+2}$

$=0.32meter$

$=30cm$

So (B) is correct answer