How can an object have negative velocity and zero acceleration?
Answer Negative velocity just means that the object is moving “backwards” [or downwards] relative to the chosen reference frame. If the acceleration is zero that means that the velocity is not changing. Therefore, the object must be moving in the negative direction at a constant speed. If the object has zero velocity, it is not moving. If it has negative acceleration its velocity is changing in the negative direction. This means that the object is at rest but is speeding up in the negative [again usually meaning “backwards”] direction.
