How is spray particle size related to terminal velocity?

The relationship between spray particle size and terminal velocity is grounded in the principles of physics, particularly the behavior of objects as they move through a fluid like air. As the size of the spray particles increases, their terminal velocity also increases. This is because larger particles experience a lower air resistance-to-gravity ratio compared to smaller particles.

In simpler terms, larger particles fall faster due to their greater mass and reduced relative surface area exposed to air resistance. The terminal velocity is the constant speed that a freely falling object eventually reaches when the resistance of the medium (in this case, air) prevents further acceleration. Therefore, as the particles become larger, they overcome the drag force more effectively, leading to a higher terminal velocity.

For those studying this topic, it is crucial to understand that smaller particles have a higher surface area to volume ratio, which leads to increased air resistance and slower falling speeds. Understanding this relationship aids in making informed decisions regarding aerial application techniques, as the size of the spray droplets can greatly affect drift, coverage, and effectiveness of pesticide applications.