Newton-meters

Definition

A newton-meter (N·m) is the unit of torque in the International System of Units (SI). It measures the amount of force applied over a distance, typically represented as the rotational equivalent of work.

5 Must Know Facts For Your Next Test

1. One newton-meter equals the torque resulting from a one newton force applied perpendicularly to a one meter lever arm.
2. Newton-meters can also be used to measure work or energy, particularly when calculating mechanical work.
3. In equations, torque ($\tau$) is often expressed as $\tau = r \times F$, where $r$ is the lever arm distance and $F$ is the force applied.
4. The unit is named after Sir Isaac Newton for his contributions to mechanics and dynamics.
5. Although commonly associated with torque, newton-meters can also describe energy, equivalent to joules.

Review Questions

• What does one newton-meter represent in terms of force and distance?
• How can you express torque using newton-meters in an equation?
• What are two contexts in which newton-meters are used?

Related terms

Torque: A measure of the rotational force on an object, calculated as force times the perpendicular distance from the pivot point.

Joule: The SI unit of work or energy, equivalent to one newton-meter.

$\text{Work}$: $\text{Work}$ measures the energy transfer when a force moves an object over a distance. Mathematically, it’s represented as $W = F \cdot d \cdot \cos(\theta)$.