
To determine the direction of angular velocity, we use the right-hand rule. If the fan is rotating counterclockwise, the angular velocity vector points along the negative \( k \)-axis, indicating the direction of rotation.
A wheel of radius $ 0.2 \, \text{m} $ rotates freely about its center when a string that is wrapped over its rim is pulled by a force of $ 10 \, \text{N} $. The established torque produces an angular acceleration of $ 2 \, \text{rad/s}^2 $. Moment of inertia of the wheel is............. kg m².