Give Reasons for the Following:

Can a body move with constant acceleration but with zero velocity? If yes, why?

Acceleration is the rate of change of velocity. In order to have non-zero acceleration, rate of change of velocity should be non-zero.

Yes, it is possible to have non-zero acceleration at zero velocity. But it is only possible for a moment. A moment is a brief period that cannot be measured.


Let us understand it by following two examples:


a) When we throw a ball in the air, it attains a maximum height and then comes down. At the maximum height velocity of the ball is zero, but a negative acceleration due to gravitation acts on it.


b) When we apply brakes on a moving car, the car stops and the velocity of the car is zero at that moment but acceleration (retardation) is not zero.


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