Joule

Definition

A joule is a unit of energy in the International System of Units (SI). It is defined as the amount of work done when a force of one newton displaces an object by one meter in the direction of the force.

5 Must Know Facts For Your Next Test

1. One joule is equivalent to $1 \, \text{N} \cdot \text{m}$ (newton-meter).
2. In integration, calculating work often involves integrating a force function over a distance.
3. The joule can also be expressed as $1 \, \text{kg} \cdot \text{m}^2 / \text{s}^2$ in terms of base SI units.
4. Joules are used to quantify energy, work, and heat.
5. When dealing with variable forces, the work done (in joules) is found by integrating the force function with respect to displacement.

Review Questions

• What is the definition of a joule in terms of newtons and meters?
• How do you calculate work in joules using integration?
• Express one joule using base SI units.

Related terms

Newton: A unit of force in the International System of Units (SI), defined as the force required to accelerate a one-kilogram mass by one meter per second squared ($1 \, \text{N} = 1 \, \text{kg} \cdot \text{m}/\text{s}^2$).

Work: The measure of energy transfer that occurs when an object is moved over a distance by an external force. Mathematically, it is often calculated as $W = \int F(x) \ dx$.

Energy: The quantitative property that must be transferred to an object to perform work on or heat it. It can exist in various forms such as kinetic, potential, thermal, etc., and is measured in joules.