Physics Motion in straight line

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Motion in straight line

Instantaneous Speed

It is measure of how fast a particle or a body is moving at a particular instant. It is the magnitude of instantaneous velocity. Thus particle moving with instantaneous velocity of+ 5m/s and another moving with -5m/s will have same instantaneous speed of 5 m/s.
The speedometer in a car measure the instantaneous speed not the instantaneous velocity, because it cannot determine the direction.

Instantaneous Velocity :

Instantaneous Velocity is defined as the value approached by the average velocity when the time interval for measurement becomes closer and closer to zero, `deltat->0 .`

`i.e. v(t) = lim_(Deltat->0) (Deltax) /(Deltat)`

Thus Instantaneous velocity function is the derivative of the displacement with respect to time.

`v(t) = (dx(t))/(dt)`