* Braking a car: When you press the brake pedal, the car's acceleration is in the opposite direction to its velocity. This causes the car to slow down.
* Throwing a ball upwards: After you release the ball, gravity acts on it, causing a downward acceleration. This acceleration opposes the ball's upward motion, eventually bringing it to a stop and then pulling it back down.
* A parachute: When a skydiver opens their parachute, the air resistance creates a strong upward acceleration. This opposes the downward motion of the skydiver, slowing them down significantly.
* A boat slowing down in water: The resistance of the water against the boat's hull creates an acceleration in the opposite direction to the boat's motion, causing it to slow down.
* A runner coming to a stop: When a runner stops running, the friction between their shoes and the ground creates a force that acts in the opposite direction to their motion, causing them to decelerate (slow down).
Key Point: Acceleration is a change in velocity. This change can be an increase in speed (positive acceleration) or a decrease in speed (negative acceleration, also known as deceleration). Acceleration is a vector quantity, meaning it has both magnitude and direction. When acceleration acts opposite to the direction of motion, it results in a decrease in speed, causing the object to slow down.
