Simpler word is speed. In physics, velocity specifically refers to the measurement of the rate and direction of change in position of an object. It is a vector quantity that specifies both the speed of a body and its direction of motion.
<em>Velocity is the rate at which the position changes</em>
<em>Velocity is the rate at which the position changesWhy do we need</em>
<em>Velocity is the rate at which the position changesWhy do we needVectors make it convenient to handle quantities going in different directions</em><em>.</em><em>.</em><em> </em>
Newton's law of cooling says that the temperature of a body changes at a rate proportional to the difference between its temperature and that of the surrounding medium (the ambient temperature); dT/dt = -K(T - Tₐ) where T = the temperature of the body (°C), t = time (min), k = the proportionality constant (per minute),