A common equation you will find in aerodynamics texts is: Drag = 1/2 * fluid density * velocity^2 * C_d * Ref. Area It approximates the drag experienced by ob

A common equation you will find in aerodynamics texts is: Drag = 1/2 * fluid density * velocity^2 * C_d * Ref. Area It approximates the drag experienced by objects as they move within a fluid (atmosphere). You can see that drag is proportional to the square of velocity, so going twice as fast induces 4 times the drag. Ergo, when you speed up, you produce a lot more drag. This will slow you down until you reach an equilibrium between thrust and drag (unless you apply more thrust).