Question
Wed August 29, 2012 By:
 

what is the deference between speed and velocity

Expert Reply
Thu August 30, 2012
Speed can be defined as the distance traveled divided by the total time taken. So, speed = distance/time.
While velocity can be defined as the displacement divided by the total time taken. So, velocity = displacement/time.

Imagine a person who ran around a circular park and returned to the same spot that he started from. The person would have covered a certain amount of distance around the circular park in a certain amount of time. If the person ran really fast, he would have used up less time to run around the park, and thus he would have a high speed. But if he ran really slowly, he would have used up more time to run around the park, and thus he would have a low speed.

But, let's move on to velocity. Because the person ran back to his starting position, he would have zero displacement. Displacement is the difference in distance between the starting and final position. So, since displacement is zero in this case, we can say that the running man has an average velocity of zero!

So speed depends on distance traveled, while velocity depends on the displacement.
 
Speed is a scalar quantity that refers to "how fast an object is moving."
Velocity is a vector quantity that refers to "the rate at which an object changes its position."
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