What is calculated by multiplying the effort force by the distance of the force from the fulcrum?

• A. Torque
• B. Power
• C. Energy
• D. Momentum

Answer: (A)

When a force is applied at some distance from a pivot, it creates a turning effect about that pivot, called torque. The torque is quantified by multiplying the force by the distance from the fulcrum (and, if the force isn’t trying to turn the lever perpendicular to it, by the sine of the angle between the force and the lever arm). This turning effect is what causes rotation, and it’s measured in Newton-meters. The other quantities describe different ideas: power is how quickly work is done, energy is the capacity to do work, and momentum is the motion of a body (mass times velocity). None of those are defined by simply multiplying force by distance from the pivot, so torque is the best-fit concept here.