Two rotating bodies `A` and `B` of masses `m` and `2 m` with moments of inertia `I_A` and `I_B (I_B gt I_A)` have equal kinetic energy of rotation. If `L_A` and `L_B` are their angular momenta respectively, then.

Options

A. `L_B gt L_A`
B. `L_A gt L_B`
C. `L_A = (L_B)/(2)`
D. `L_A = 2 L_B`

Answer

A

Explanation

(a) `K_A = K_B rArr (L_A^2)/(2 L_A) =(L_B^2)/(2 I_B)`
because `I_B gt I_A :. L_A^2 lt L_B^2 rArr L_A lt L_B`.