Chapter 13 - A Preview of Calculus: The Limit, Derivative, and Integral of a Function - Section 13.4 The Tangent Problem; The Derivative - 13.4 Assess Your Understanding - Page 916: 5

Velocity

Let $s(t)$ be the position function of the particle. The velocity of the particle can be defined as the rate of change of the position function and can be written as: $v(t)=\dfrac{d (s(t))}{dt}$. Or, in alternative notation, $v(t)=s'(t)$