Question

A constant torque of $31.4N-m$ is exerted on a pivoted wheel. If angular acceleration of wheel is $4\pi rad/s^2$, then the moment of inertia of the wheel is

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

Answer 1

The correct option is A $2.5kg\text{-}{m}^2$

$\tau =I\alpha$

$31.4=I\times 4\pi$

$31.4=I\times 4\left(3.14\right)⟹I=2.5kg{m}^2$