milliJoules

**Millijoules**

A millijoule (symbol: mJ) is a unit of energy in the International System of Units (SI). It represents one-thousandth of a joule, where one joule is defined as the amount of energy transferred (or work done) when a force of one newton acts over a distance of one meter. The millijoule is commonly used in scientific, engineering, and everyday applications where smaller energy measurements are required.

In practical terms, a millijoule is equivalent to 0.001 joules or 10^-3 joules. This unit is frequently encountered in fields such as physics, electronics, and biochemistry, where energy levels are often measured in very small quantities. For example, a typical smartphone flashlight might emit energy in the range of millijoules per pulse, while a small electronic circuit might consume millijoules per second during operation.

The millijoule is also used in the context of radiation dosimetry, where it quantifies the energy absorbed by a material per unit mass. In this application, it helps in assessing the biological effects of radiation exposure. Additionally, in energy storage devices like batteries, millijoules may be used to describe the energy capacity of micro-scale components.

Understanding millijoules is essential for precise measurements in various scientific and technological disciplines, ensuring accurate calculations and comparisons across different systems.