text: velocity a vector quantity that has both speed and direction...\nuniform velocity is a body's speed and direction is not changing... thus, has zero acceleration...\nvariable velocity is either the boddy's speed or direction is changing or both speed and direction is changing... this means that the acceleration of the body is non-zero.... it may be constant acceleration or also varrying...\n\nspeed is scalar, only with magnitude...\nvelocity is vector both with speed and direction...\nacceleration is vector, to say A CHANGE in speed or direction...