1. The problem statement, all variables and given/known data I need to find the approximate terminal velocity of a baseball shaped concrete sphere and what distance it would take to reach that terminal velocity if dropped on earth under normal weather conditions. I have found that a baseball made of concrete would have a mass of approximately .5307 kg, radius of 1.46 inches and a cross sectional area of .004321 m^2 I know that the acceleration due to gravity is 9.8 m/s^2 and according to wikipedia the air density of dry air at sea level at 20 degress celsius is 1.2 kg/m^3 Using wikipedia I found the equation for the terminal velocity. http://en.wikipedia.org/wiki/Terminal_velocity I am having trouble finding the approximate drag coefficient of the concrete sphere. Is there anyway to estimate this to get a reasonably close value, or must it be derived experimentally?