How is torque defined in physics?

Torque is defined as the measure of the rotational force acting on an object, which is crucial in understanding how forces cause objects to rotate around an axis. Mathematically, torque is calculated by multiplying the force applied to an object by the distance from the pivot point (or fulcrum) to the line of action of the force. This distance is often referred to as the moment arm.

When a force is applied at a certain distance from an axis, it creates a tendency for the object to rotate around that axis. The larger the force or the greater the distance (moment arm), the greater the resulting torque, which can significantly affect the motion of the object. Understanding torque is essential in many practical applications, such as using wrenches to tighten bolts, analyzing the balance of levers, or understanding the physics of rotating machinery.

The other options do not accurately describe torque. Linear force relates to movements along a straight path rather than rotation. The product of mass and acceleration refers to Newton's Second Law of Motion and describes linear force. The net force acting on an object pertains to the overall force considering various acting forces, which again does not encompass the rotational aspects that torque represents.