The turning effect of a force around a pivot, calculated as force × distance, is known as

• A. Torque
• B. Leverage
• C. Moment
• D. Angle

Answer: (C)

The turning effect of a force about a pivot is called the moment. It tells you how strongly the force tends to rotate the object and is found by multiplying the force by the distance from the pivot to the line of action of the force (F × d). When the force acts at right angles to the lever arm, d is simply the length of the arm. The units are newton-metres (N·m). In many contexts this turning effect is also called torque, but for this topic the standard term used is moment. The idea that what we’re measuring is a rotational tendency separates it from angle, which is a measure of rotation itself, and from leverage, which describes mechanical advantage rather than the rotating effect about a pivot.