Suggested languages for you:

Americas

Europe

Q15CQ

Expert-verified
Found in: Page 79

### College Physics (Urone)

Book edition 1st Edition
Author(s) Paul Peter Urone
Pages 1272 pages
ISBN 9781938168000

# Give an example in which velocity is zero yet acceleration is not.

Ball going up and coming down when the ball is at top velocity is zero, but acceleration is $\mathbf{g}\text{=}\left(\mathbf{9}.\mathbf{81}\text{}\mathbf{m}/{\mathbf{s}}^{2}\right)$.

See the step by step solution

## Step 1: Acceleration and its unit

The rate at which an object's velocity changes with respect to time is called acceleration.

An item experiences acceleration whenever its velocity changes.

As a result, there is a non-zero value of acceleration whenever the magnitude or direction of the velocity changes.

## Step 2: instantaneous Acceleration

The rate at which an object's velocity changes in relation to the time it takes for that change to occur is called acceleration. When a body's velocity is zero, it is conceivable to have a non-zero acceleration value.

This can happen when it moves in one direction and is acted upon by a force that moves in the other direction.

The object's velocity begins to drop as a result of this force and continues to decline until it approaches zero. Following that, the item begins to move in the other direction (that is, in the direction of force).

Only the instantaneous velocity of the body is zero at the moment where the velocity becomes zero; the item has a non-zero velocity at any time before or after this point.

This indicates that even after the object's velocity hits zero, the change in velocity continues. As a result, the body continues to accelerate.

## Step 3: instantaneous Acceleration value when velocity is zero

When a ball is hurled upwards at a steady velocity on Earth, the gravitational pull of the earth operates in the opposite direction on it.

The ball's velocity reaches zero at its greatest point, following which it begins to descend. The ball's velocity is zero at this point, but its acceleration is equal to $\mathbf{g}\text{=}\left(\mathbf{9}.\mathbf{81}\text{}\mathbf{m}/{\mathbf{s}}^{2}\right)$.

The restoring force takes over when the maximum displacement is reached, and the object begins to accelerate in the opposite direction.

The object's velocity is zero at this moment as well, but it has some acceleration equivalent to the restoring force.

Therefore, Ball going up and coming down when the ball is at top velocity is zero, but acceleration is $\mathbf{g}\text{=}\left(\mathbf{9}.\mathbf{81}\text{}\mathbf{m}/{\mathbf{s}}^{2}\right)$.