NEET-XI-Physics
exam-2 year:2016
- #122A light rod of length l has two masses ``m_1`` and ``m_2``
attached to its two ends. The moment of inertia of
the system about an axis perpendicular to the rod
and passing through the centre of mass is :-
(1) (``m_1``+ ``m_2``)``l^2 ``
(2)``\sqrt{m_1+ m_2}`` ``l^2``
(3) ``\frac{m_1m_2}{m_1 + m_2}````l^2``
(4) ``\frac{m_1 + m_2}{m_1m_2}````l^2``digAnsr: 3Ans : (3)
Sol.
r1 r2
(CM)m1 m2
2
1
1 2
m
r
m m
=
+
,
1
2
1 2
m
r
m m
=
+
2 2
cm 1 1 2 2I m r m r= +
21 2
1 2
m m
m m
=
+