Question

A constant torque of $31.4Nm$ is exerted on a pivoted wheel. If angular acceleration of wheel is $4\pi rad{s}^{-2}$, then the moment of inertia of wheel is nearly equal to

• A. $3.5kg{m}^2$
• B. $2.5kg{m}^2$
• C. $4.5kg{m}^2$
• D. $5.5kg{m}^2$

Answer 1

The correct option is B $2.5kg{m}^2$

Given,
$\tau =31.4Nm\alpha =4\pi rad{s}^{-2}$
Relation between torque and angular acceleration is
$\tau =I\alpha \Rightarrow I=\frac{31.4}{4\pi }=2.5kg{m}^2$