* Acceleration is a vector: Acceleration has both magnitude (how fast the velocity is changing) and direction. Negative acceleration simply means the acceleration is in the opposite direction to the object's current velocity.
* Think of throwing a ball up: When you throw a ball straight up, it experiences a constant negative acceleration due to gravity. Even though the acceleration is negative, the ball initially travels upwards. As the ball slows down, it eventually stops and then changes direction, falling back down.
Example:
Imagine a car moving to the right with a positive velocity. If it has a constant negative acceleration, this means the car is slowing down. Eventually, the car will come to a stop. If the negative acceleration continues, the car will start moving to the left (the opposite direction).
Key takeaway: Constant negative acceleration doesn't necessarily mean an object will *always* move in the negative direction. It simply means the acceleration is acting in the opposite direction to the object's current velocity. This can lead to a change in direction if the acceleration is strong enough to overcome the initial velocity.
