Equations · equation
Newton–Laplace Speed of Sound
Acoustics · 1816
- Equation
- c = √(γp/ρ)
- Field
- Acoustics
- Named After
- Isaac Newton · Pierre-Simon Laplace
- Symbols
- c speed of sound · p pressure · ρ density · γ adiabatic index (about 1.4 for air) — roughly 343 m/s in room-temperature air
- Year
- 1816
Significance
How fast pressure waves travel through a gas. Newton derived it first in 1687 and came out 15% slow by assuming compression at constant temperature; Laplace's adiabatic correction — sound compresses air too fast for heat to escape — made theory match experiment.
Referenced by
element
equation
Open on the Equations shelf — the interactive card, the filters, and everything alongside it.