see explanation below

Speed is the distance travelled per unit time irrespective of direction, so only magnitude is of importance, and that it is a scalar quantity. Speed can be calculated using the formula: ##(distance)/(time)##

Velocity is the distance travelled per unit time in a specific direction, so both magnitude and direction are important, and that it is a vector quantity. Velocity can be calculated using the formula: ##(displacement)/(time)##

is the rate of change of velocity of an object. Magnitude and direction are both considered, so it is a vector quantity. Acceleration can be calculated using the formula: ##a=(v-u)/t##, where ##a##=acceleration, ##v##=final velocity, ##u##=initial velocity and ##t##=time.