* A car braking to a stop: The car is moving forward (direction of motion), but the brakes apply a force in the opposite direction (acceleration). This deceleration causes the car to slow down.
* A ball thrown upwards: As the ball travels upwards, gravity acts on it, pulling it downwards (acceleration against the direction of motion). This causes the ball to slow down until it momentarily stops at its highest point.
* A boat slowing down while rowing upstream: The rower is pushing the boat forward (direction of motion), but the current of the river exerts a force against the boat's movement (acceleration against the direction of motion). This causes the boat to slow down.
* A runner coming to a stop: The runner is moving forward (direction of motion), but their feet push backward against the ground (acceleration against the direction of motion). This deceleration brings them to a stop.
In all of these examples, the force causing the acceleration is acting in the opposite direction of the object's motion. This results in the object slowing down, which is called deceleration or negative acceleration.
