NTA Abhyas JEE Main2020PhysicsRotational MotionPractice
A uniform square plate of mass m is supported with its plane vertical as shown in the figure. Assume the centre of mass is on a horizontal line passing through A . If the cable at B breaks then just after that the angular acceleration of the plate is
Options
- A3 g 2 2 b
- B3 g 2 b
- Cg 2 b
- D2 g 3 b
Correct answer
A. 3 g 2 2 b
Step-by-step solution
The plate will rotate about the hinged point ( point A ) after breaking of the cable ∴ using τ = Iα for the plate Mg b 2 = 2 3 Mb 2 α ( Moment of inertia about point A is Mb 2 6 + M b 2 2 = 2 3 Mb 2 ) ∴   α = 3 g 2 2 b