A mass \(m\) is in rest on an inclined plane of mass \(M\) which is further resting on a smooth horizontal…

A mass \(m\) is in rest on an inclined plane of mass \(M\) which is further resting on a smooth horizontal plane. Now, if the mass \(m\) starts moving under gravity, the position of centre of mass of system will
  1. remain unchanged
  2. change along the horizontal direction
  3. move up in vertical direction
  4. move down in the vertical direction and changes along the horizontal

Solution

The given situation is shown in the following figure.
Clearly when mass \(m\) starts moving under gravity, hence net force on the system in horizontal direction is zero. Therefore, centre of mass of the system will not move in horizontal direction. Now, for vertical direction there is a net force that is the mass of the wedge and the block and hence the centre of mass changes in this direction.

Asked in: AP EAMCET 2020 (18 Sep Shift 1)

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