NEET2012PhysicsRotational MotionActual
A circular platform is mounted on a frictionless vertical axle. Its radius R=2 ~m and its moment of inertia about the axle is 200 ~kg ~m ^2 . It is initially at rest. A 50 ~kg man stands on the edge of the platform and begins to walk along the edge at the speed of 1 ~ms ⁻¹ relative to the ground. Time taken by the man to complete one revolution is
Options
- A3 2
- B2 sec
- C2
Correct answer
C. 2
Step-by-step solution
From conservation of angular momentum aligned I & =m v r 200 & =50 2 1 & = 1 2 rad / s aligned aligned v & =r =1 ~m / s T & = 2 r 1-(-1) = 2 r 2 = r=2 s aligned