# Air Resistance Constant

Hey im just wondering about something, air Resistance is proportional to the velocity in some cases or velocity squared in others.

dV/dt=kv what is a typical constant for k, i know it varies so lets just say a baseball at sea level(im sure you all can guess why im asking this.... ) Also is there a way to calculate this "k"...
any help greatly appreciated thanks!

It depends very much on the shape and texture of objects, if you use the formula $$D = \frac{1}{2}CA\rho v^2$$. For a spherical body like the baseball it should be around 0.5.