Moment Arm (Lever Arm)
Definition
The perpendicular distance from the axis of rotation to the line of action of the force. Effective moment arm = r × sin(θ) when force is not perpendicular to the radial line.
Practical Note
Longer moment arm = less force needed for same torque. This is why breaker bars and cheater pipes increase torque capability. Double the arm length = half the force needed.
Related Calculators
🔄Torque Calculator
Calculate torque from force and lever arm, convert between torque units, and determine force or distance for required torque. Includes angular acceleration calculations.
⚙️Gear Ratio Calculator
Calculate gear ratios, output RPM, and torque for gear trains. Includes animated visualization of gear rotation.