Torque

Torque is the turning effect of a force about an axis, equal to the force multiplied by its perpendicular lever arm. Its direction is represented by a vector along the axis of rotation.

Moment arm: The perpendicular distance from an axis of rotation to a force’s line of action. Torque grows with this distance, which determines the force’s rotational leverage.
Force: An interaction that changes or tends to change an object's motion. Torque describes the rotational effect of this underlying interaction.
Internal combustion engine: An engine that produces mechanical power by burning fuel inside its cylinders. Combustion pressure applies torque to the crankshaft to drive the vehicle.
Work (physics): Energy transferred when a force acts through a displacement. Torque is a turning effect; work measures energy transfer during angular displacement.
Cross product: A vector operation that produces a vector perpendicular to two input vectors, with magnitude proportional to their angle. The cross product of position and force encodes torque’s magnitude and axis direction.
Lever: A rigid bar that pivots around a fulcrum to transmit or amplify force. A lever makes the relationship between force, pivot, and turning effect concrete.
Electric motor: A machine that converts electrical energy into mechanical rotation. Motor ratings often specify torque, which governs the turning force available at the shaft.
Angular momentum: A vector quantity describing rotational motion, determined by a body's motion and mass distribution. Torque changes angular momentum, but is not itself a measure of rotational motion.
Net force: The vector sum of all forces acting on an object. A force’s torque can cause rotation even when the net force is zero.
Newton's laws of motion: Three classical laws relating an object's motion to forces acting on it. Torque extends the force-and-motion framework to rotational dynamics.

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