Definition

Noun: A measure of a substance's resistance to uniform compression. It is defined as the ratio of the infinitesimal pressure increase to the resulting relative decrease in volume.

Usage

The term "bulk modulus" is used in physics and engineering to describe the elastic properties of materials, particularly their incompressibility. It quantifies how much pressure is needed to achieve a given volume reduction.

Examples

• Solids like diamond have a very high bulk modulus, indicating they are difficult to compress.
• To calculate the compressibility of the fluid, you need to know its bulk modulus.
• The bulk modulus is a critical parameter in acoustics for determining the speed of sound in a material.

Advanced Usage

• Reciprocal Relationship: The inverse of the bulk modulus is called the compressibility. A high bulk modulus means low compressibility.
• Temperature and Pressure Dependence: The value of the bulk modulus is not a constant for a given material; it can vary with temperature and pressure.

Variants and Related Words

• Shear Modulus (Noun): A measure of a material's resistance to shear deformation (shape change without volume change).
• Young's Modulus (Noun): A measure of a material's resistance to linear (tensile or compressive) strain.
• Modulus of Elasticity (Noun): A general term for any measure of a material's stiffness, including bulk, shear, and Young's modulus.

Synonyms

• Volume modulus
• Compression modulus

Related Phrases

• Isentropic bulk modulus: The bulk modulus measured under conditions of constant entropy, relevant for rapid processes like sound waves.
• Isothermal bulk modulus: The bulk modulus measured under conditions of constant temperature.

Noun

1. the ratio of the change in pressure acting on a volume to the fractional change in volume