Joule

Definition

A joule is the SI unit of work or energy, equivalent to one newton-meter. It measures 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 equal to $1 \text{N} \cdot 1 \text{m}$.
2. The joule is named after James Prescott Joule, an English physicist.
3. In electrical terms, one joule is equal to one watt-second.
4. The joule can be used to measure any form of energy including kinetic, potential, and thermal energy.
5. One calorie is approximately equal to 4.184 joules.

Review Questions

• What is the SI unit for work and energy?
• How many joules are in one watt-second?
• Who was the joule named after?

Related terms

Newton:

The SI unit of force, defined as the amount of force required to accelerate a mass of one kilogram by one meter per second squared.

Watt:

The SI unit of power, equivalent to one joule per second.

Calorie: A unit of energy commonly used in chemistry and nutrition, where one calorie is approximately equal to 4.184 joules.