Two blocks of masses 10 kg and 20 kg are placed on the X-axis. The first mass is moved on the axis by a distance of 2 cm. By what distance should the second mass be moved to keep the position of the centre of mass unchanged?
Let the centre of mass of the system be its origin.
Initial position of 10kg mass = (-x1,0)
Initial position of 20kg mass = (x2,0)
Final position of 10kg mass = (-x1+2,0)
Final position of 20kg mass = (x2+x,0)
Coordinates of the centre of mass corresponding to initial and final positions stays same.
On solving, we get x = -1
∴ The 20 kg block must be moved 1cm towards the centre of mass to keep the centre of mass of the system unchanged.
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