Question

A flywheel rotating a fixed axis has a kinetic energy of 360 joule when its angular speed is 30 radii sec then moment of inertia of the wheel about of rotation is:

• A. 0.6kg x $m^2$
• B. 0.15 kg x $m^2$
• C. 0.8 kg x v
• D. 0.75 kg x $m^2$

Answer 1

The correct option is C 0.8 kg x v

K.E.$=\frac{I{\omega }^2}{2}$

$2=\frac{2KE}{{\omega }^2}$

$\Rightarrow \omega =30$

K.E$=360$

$=\frac{2\times 360}{30\times 30}$

$=0.8$kg $m^2$

$\therefore I=0.8$kg $m^2$

Answer is C.