1. What is Bulk Modulus?

The bulk modulus (K) is a measure of a substance's resistance to uniform compression. It's defined as the ratio of the infinitesimal pressure increase to the resulting relative decrease of the volume.

2. How Does the Calculator Work?

The calculator uses the bulk modulus equation:

Where:

• \( K \) — Bulk modulus (Pa)
• \( \rho \) — Density (kg/m³)
• \( v_p \) — P-wave velocity (m/s)
• \( G \) — Shear modulus (Pa)

Explanation: The equation relates bulk modulus to density, seismic P-wave velocity, and shear modulus of a material.

3. Importance of Bulk Modulus

Details: Bulk modulus is crucial in geophysics, material science, and engineering for understanding material compressibility and wave propagation.

4. Using the Calculator

Tips: Enter density in kg/m³, P-wave velocity in m/s, and shear modulus in Pa. All values must be positive (shear modulus can be zero).

5. Frequently Asked Questions (FAQ)

Q1: What are typical bulk modulus values?
A: Water has a bulk modulus of about 2.2 GPa, while steel is around 160 GPa. Rocks typically range between 5-100 GPa.

Q2: How is bulk modulus related to compressibility?
A: Compressibility is the reciprocal of bulk modulus. Higher bulk modulus means less compressible material.

Q3: What's the difference between bulk and shear modulus?
A: Bulk modulus measures resistance to volume change, while shear modulus measures resistance to shape change.

Q4: When is the (4/3)G term significant?
A: For fluids (G=0), this term disappears. For solids, it accounts for shear wave contribution to P-wave velocity.

Q5: How does temperature affect bulk modulus?
A: Generally, bulk modulus decreases with increasing temperature as materials become more compressible.