What is a typical constant for air resistance in relation to velocity?

[BigStelly]

Hey I am 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 let's just say a baseball at sea level(im sure you all can guess why I am asking this... ) Also is there a way to calculate this "k"...
any help greatly appreciated thanks!

 

[ramollari]

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.
Have a look here also: http://www.ac.wwu.edu/~vawter/PhysicsNet/Topics/Dynamics/Forces/DragCoeficientValues.html for a table of constants.