Drag is the force that opposes the motion of an object moving through a fluid (liquid or gas). It is directly proportional to the square of the object's velocity, which means that drag increases as the object moves faster.

When an object is moving slowly, the fluid particles have more time to flow around the object and exert less force on it. This is because the boundary layer, which is the layer of fluid that is in contact with the object's surface, is thinner at lower speeds. The thinner boundary layer means that there is less friction between the fluid and the object's surface, which results in less drag.

As the object's velocity increases, the boundary layer becomes thicker and the fluid particles have less time to flow around the object. This causes the friction between the fluid and the object's surface to increase, which results in more drag.

Another factor that contributes to the increased drag at higher speeds is the formation of a turbulent boundary layer. When the object's velocity exceeds a certain critical value, the boundary layer becomes turbulent and the fluid particles start to swirl and eddy around the object. This turbulence causes even more friction between the fluid and the object's surface, which further increases drag.

Therefore, the drag less if an object moves slowly because there is less friction between the fluid and the object's surface.