Question

Two blocks of masses 10 kg and 30 kg are placed on the same straight line with coordinates(0, 0) cm and (x, 0) cm respectively. The block of 10 kg is moved on the same line through a distance of 6 cm towards the other block. The distance through which the block of 30 kg must be moved to keep the position of Centre of mass of the system unchanged is

• A. 4 cm towards the 10 kg block
• B. 2 cm away from the 10 kg block
• C. 2 cm towards the 10 kg block
• D. 4 cm away from the 10 kg block

Answer 1

Answer: (C)

2 cm towards the 10 kg block

Answer 2

For COM to remain unchanged,

$m_1x_1 = m_2m_2$

$⇒ 10 × 6 = 30 × x_2$

$⇒ x_2 = 2$ $cm$ towards $10$ $kg$ block.

Therefore, the correct option is (C): $2$ $cm$ towards the $10$ $kg$ block