KVPY2017PhysicsRotational Motion
A solid cube of wood of side 2 a and mass M is resting on a horizontal surface as shown in the figure. The cube is free to rotate about the fixed axis AB . A bullet of mass m (
Options
- A3 gM / 2 ma
- B3 g / 4 h
- C3 g( 2 -1) / 2 a
- D3 g( 2 -1) / 4 a
Correct answer
D. 3 g( 2 -1) / 4 a
Step-by-step solution
conservation of energy array l 1 2 I _ A _ c ²= Mg ( a 2 - a ) I _ A = I _ cm + Ma ²= 2 3 Ma ²+ M ( a 2 )² I _ A = 8 9 Ma ² 1 2 8 3 Ma ² _ c ²= Mg a ( 2 -1) _ c = 3 ~g ( 2 -1) / 4 a array