Remark — Why they are important
The unknown is not a quantity, but a function: it is the function that describes how a cup of coffee cools, how a radioactive substance decays, how a spring oscillates.
Every time a physical quantity changes over time at a rate that depends on its current value, the equation describing it is a differential equation. This is the language in which physics formulates its laws: Newton’s second law, radioactive decay, cooling, oscillators, electrical circuits are all differential equations.
Links
Topics: Differential equations
Concepts: Differential equation
Skills: Modelling