Which statement is true? a. speed is a scalar quantity and velocity is a vector quantity. b. speed and velocity are both scalar quantities. c. speed and velocity are both vector quantities. d. speed is a vector quantity and velocity is a scalar quantity. e. speed and velocity are neither a scalar quantity nor a vector quantity.

A. Speed is a scalar quantity and velocity is a vector quantity.

Explanation:

A scalar quantity is one that consists of only a numerical value.

Speed is a scalar quantity because only the instantaneous value is indicated, for example the speedometer of a car that tells you your speed at the moment but not where you are going or in what direction are you going.

On the other hand, velocity is a vector quantity. Because it is composed of a magnitude and a direction, for example 10m/s to the south is a velocity, and 10m/s is a speed.