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In practical life we see objects not actually moving on same way as of displacement,They cover distance.

While studying physics why do we study displacement and velocity.

Is there any practical use of displacement and velocity.

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closed as unclear what you're asking by John Rennie, Ross Millikan, Kyle Kanos, ACuriousMind, user10851 Aug 26 '15 at 18:43

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    $\begingroup$ How much distance does a pendulum cover? $\endgroup$ – Jon Custer Aug 25 '15 at 16:54
  • $\begingroup$ I have no idea what "Is there any practical use of velocity?" is supposed to mean. Stuff moves. It does so with a certain velocity. What "practical use" has there to be to this fact? $\endgroup$ – ACuriousMind Aug 25 '15 at 23:31
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If you drive along the road on the side of a mountain) there are (at least) two kinds of forces on your car: friction and gravity.

If you drive to the top of the mountain and back, the net work done against gravity is zero. This corresponds to the fact that your displacement is zero.

On the same trip, you had to overcome friction. That depended on your instantaneous velocity, and the distance you traveled. Although you returned to your starting point, you traveled a non-zero distance and did net work.

In physics we recognize two kinds of force fields: conservative, and non-conservative. Gravity is an example of a conservative field; friction, an example of non-conservative field. When you move in a conservative field, the total work done is a function of just "where did you start" and "where did you finish". For a non-conservative field like friction, how you got from A to B matters: we call that "path dependent".

Since both situations occur all the time, we have to study (and be familiar with) both.

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    $\begingroup$ That is a pretty awesome answer to explain it to somebody who is new to physics. $\endgroup$ – Karan Singh Aug 25 '15 at 17:24

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