# speed and velocityi see no differencebetween the terms but my teacher says that it is.

pohnpei397 | Certified Educator

The difference is that velocity has a direction to it and speed does not.  If you are going to be technically correct, you have to talk about the velocity of an object in a specific direction.  Speed can be given regardless of direction, but velocity must have a direction -- it is a vector quantity while speed is a scalar quantity.

litteacher8 | Certified Educator
The second response is a good one. Basically, both speed and velocity involve movement. Speed is how fast an object is moving, whereas velocity is speed in a specific direction. So by that logic, speed is a less specific term than velocity, because it does not include direction.
giorgiana1976 | Student

Speed is a scalar quantity and velocity is a vector quantity. As we know, a vector is described by magnitude and direction, meanwhile the scalar quantity is described only by the magnitude.

So, when we want to determine the rate of changing a position of an object, we'll have to calculate the velocity. If we want just to know how fast is moving that object, we'll have to determine only the speed.