Torque on a uniform disk of mass $2\text{ }\text{kg}$, radius $1\text{ }\text{m}$, is given as $\tau (t)=5{t}^{2}−8t$. If the disk was initially at rest, find the power by torque at $t=1\text{ }\text{s}$.

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YESPYQ · Accepted Answer

Correct answer: c) 7 W. (3) $ \begin{aligned} & \rho=\vec{\tau} \cdot \vec{\omega} \ & \tau=l \alpha \ & I=\frac{M R^2}{2}=1 \ & \alpha=5 t^2-8 t \ & \omega=\frac{5}{3} t^3-4 t^2 \ & \text { At } t=1, \omega=\frac{5}{3}-4=-\frac{7}{3} \ & t(3)=5-8=-3 \ & \rho=\vec{\tau} \cdot \vec{\omega}=7 \mathrm{~W} \end{aligned} $

Torque on a uniform disk of mass \(2\text{ }\text{kg}\), radius \(1\text{ }\text{m}\), is given as \(\tau (t)=5{t}^{2}−8…

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