Physics

Physics
Calculus is of vital importance in physics: many physical processes are described by equations involving derivatives, called differential equations . Physics is particularly concerned with the way quantities change and evolve over time, and the concept of the "time derivative" — the rate of change over time — is essential for the precise definition of several important concepts. In particular, the time derivatives of an object's position are significant in Newtonian physics:
• Velocity is the derivative (with respect to time) of an object's displacement (distance from the original position)
• Acceleration is the derivative (with respect to time) of an object's velocity, that is, the second derivative (with respect to time) of an object's position.
For example, if an object's position on a line is given by



then the object's velocity is



and the object's acceleration is



which is constant.

Taken From http://en.wikipedia.org/wiki/Differential_calculus#Calculus_of_variations