Define acceleration.

Explanation

Acceleration of a body is its rate of change of velocity with time.
Form Newton.s 2nd law, the acceleration `vec(a)` of a body of mass m is related to an applied force `vec(F)` as, `vec(F) = m vec(a)`. So, when the body is acted upon by a constant force `vec(F)`, we get `vec(a)` = constant. Thus, the body moves with a uniform acceleration.