JEE Main20198 Apr 2019Evening ShiftPhysicsCenter of Mass, Momentum and CollisionActual
A uniform rectangular thin sheet A B C D of mass M has length a and breadth b , as shown in the figure. If the shaded portion H B G O is cut-off, the coordinates of the centre of mass of the remaining portion will be:
Options
- A5 a 12 , 5 b 12
- B5 a 3 , 5 b 3
- C2 a 3 , 2 b 3
- D3 a 4 , 3 b 4
Correct answer
A. 5 a 12 , 5 b 12
Step-by-step solution
If the total mass of object mass M then the mass removed part will be M 4 . X C M = M · a 2 - M 4 3 a 4 M - M 4 = M a 2 - 3 M a 16 3 M 4 = 5 12 a Y C M = M · b 2 - M 4 3 b 4 M - M 4 = M b 2 - 3 M b 16 3 M 4 = 5 12 b