System Of Particles And Rotational Motion Ques 73
73. A fly wheel rotating about a fixed axis has a kinetic energy of $360$ joule when its angular speed is $30$ $ radian / sec$. The moment of inertia of the wheel about the axis of rotation is
[1990]
(a) $0.6 $ $kg / m^{2}$
(b) $0.15$ $ kg $ $m^{2}$
(c) $0.8 $ $kg $ $m^{2}$
(d) $0.75$ $ kg $ $m^{2}$
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Answer:
Correct Answer: 73.(c)
Solution:
- (c) $E_r=\frac{1}{2} I \omega^{2}$
$I=\frac{2 E_r}{\omega^{2}}=\frac{2 \times 360}{30 \times 30}=0.8 $ $kg$ $ m^{2}$
BETA
