* Velocity tells us the speed and direction of an object's motion.
* Acceleration tells us how the velocity is changing.
If acceleration is in the opposite direction of velocity, it means the object is experiencing a force that is working to reduce its speed. This is known as deceleration or negative acceleration.
Examples:
* A car braking to a stop. The car's velocity is forward, but the brakes cause an acceleration in the opposite direction (backward), slowing the car down.
* A ball thrown vertically upwards. As it rises, its velocity is upwards, but gravity acts downwards causing deceleration. The ball eventually stops and then accelerates downwards.
Key Point: When acceleration and velocity are in the same direction, the object is speeding up. When they are in opposite directions, the object is slowing down.
