How

fast or at what

speed a particle or point is

moving **at a given instant**. Also called,

velocity.

Velocity at any instant is obtained from the average velocity by shrinking the time interval *t* between the minimum speed and maximum speed until it infinitely approaches 0. As *t* shrinks, the average velocity approaches a limiting value, which is the velocity at that instant.

*v = lim t->0 (x/t) = ***dx/dt**