AP EAMCET2007PhysicsRotational Motion
Two solid spheres ( A and B ) are made of metals of different densities _A and _B respectively. If their masses are equal, the ratio of their moments of inertia (I_B / I_A ) about their respective diameter is
Options
- A( _B _A )^ 2 / 3
- B( _A _B )^ 2 / 3
- C_A _B
- D_B _A
Correct answer
A. ( _B _A )^ 2 / 3
Step-by-step solution
As two solid spheres are equal in masses, so m_A=m_B aligned & 4 3 R_A^3 _A & = 4 3 R_B^3 _B & R_A R_B & = ( _B _A )^ 1 / 3 aligned The moment of inertia of sphere about diameter I= 2 5 m R^2 array ll & I_A I_B = ( R_A R_B )^2 ( as m_A=m_B ) & I_A I_B = ( _B _A )^ 2 / 3 array