* Velocity: Velocity is a vector quantity, meaning it has both magnitude (speed) and direction. A negative velocity simply means the object is moving in the opposite direction to whatever we've defined as positive. For example, if "up" is positive, then an object moving down has a negative velocity.
* Acceleration: Acceleration is the rate of change of velocity. It also has both magnitude and direction. Negative acceleration means the velocity is decreasing in the positive direction, or increasing in the negative direction.
Examples:
1. A car braking: If a car is moving forward (positive velocity) and applies the brakes, it experiences negative acceleration. This slows it down, meaning its velocity is decreasing in the positive direction.
2. A ball thrown upwards: As a ball travels upwards, its velocity decreases until it reaches its highest point. During this upward journey, its velocity is positive, but its acceleration is negative due to gravity.
Important Note: The signs of velocity and acceleration depend on the chosen coordinate system. If you switch the direction of the positive axis, the signs of velocity and acceleration will also change.
