Question

A wheel with mass m = 1 kg under the action of a moment of 3 Nm, rotates at an angular acceleration of 0.5 rad / s². Find the radius of the wheel.

Answer 1

We can find the radius of the wheel as follows:

$$\tau=I\alpha,$$ $$\tau=\dfrac{1}{2}mr^2\alpha,$$ $$r=\sqrt{\dfrac{2\tau}{m\alpha}}=\sqrt{\dfrac{2\cdot3\ N\cdot m}{1\ kg\cdot0.5\ \dfrac{rad}{s^2}}}=3.5\ m.$$