A body experiences both positive velocity and negative acceleration when it is moving in a particular direction but slowing down. This occurs when the body is moving in the positive direction (increasing its displacement) but its acceleration is in the opposite direction, i.e., negative.
To understand the direction of motion in this situation, let's consider a simple example. Suppose a car is initially moving in the positive direction along a straight road. As the car applies its brakes, it starts to slow down. At this point, the car's velocity is still positive because it is moving in the positive direction. However, the acceleration due to braking is in the opposite direction (negative), opposing the car's motion.
If the car continues to decelerate, eventually the acceleration will cause its velocity to decrease to zero. At this moment, the car's velocity changes direction. After reaching zero velocity, if the acceleration continues to act in the negative direction, the car's velocity becomes negative, and it starts moving in the opposite direction (negative direction).
In summary, when a body experiences both positive velocity and negative acceleration, it means the body is slowing down while moving in the positive direction. If the acceleration persists, the body's velocity will eventually change direction and become negative, causing it to move in the opposite direction.