Here's why:
* Acceleration is the rate of change of velocity. This means if velocity is changing, the acceleration cannot be zero.
* Velocity is a vector quantity, meaning it has both magnitude (speed) and direction.
* Acceleration can occur due to a change in speed, a change in direction, or both.
Examples:
* A car speeding up: The car's velocity is increasing, so it has a non-zero acceleration.
* A car slowing down: The car's velocity is decreasing, so it has a non-zero acceleration (in the opposite direction of motion).
* A car turning a corner at constant speed: The car's direction is changing, so it has a non-zero acceleration (towards the center of the turn).
When is acceleration zero?
Acceleration is zero only when the velocity of the body is constant, meaning both the speed and direction are not changing. For example:
* A car moving at a steady speed in a straight line.
Let me know if you'd like more examples or explanations!
