Final answer:
In physics, a body can have negative acceleration but never negative speed because negative acceleration refers to deceleration or slowing down, while speed refers to the absolute value of velocity.
Step-by-step explanation:
In physics, a body can have negative acceleration but never negative speed. Negative acceleration occurs when an object is slowing down or decelerating. The object's velocity may be positive or negative, depending on its direction of motion.
For example, if a car is moving in the positive direction but slowing down, its acceleration is negative because it is opposite to its direction of motion. However, its speed will still be positive because it is moving in the positive direction.
Therefore, although a body may have negative acceleration, its speed will always be positive regardless of its direction of motion.