Any falling object starts at 0 downward velocity (unless it has been pushed down, which only gets you to terminal V faster). The force gravity exerts on the object increases the object's velocity. The object's velocity will continue to increase because of gravity until the object runs into something, namely the ground. Or at least this is how physics goes in a vacuum where there is no air resistance. Air resistance , or drag, happens because there are particles in the air (oxygen, hydrogen, etc), and as an object falls the object interacts with the particles (by dropping on them). For every action there is an equal and opposite reaction, and so these particles also exert a force on the falling object (by pushing back up). Granted this is not enough force to push the object back up, or even to stop the object. As the velocity of the object increases, so does the amount of force the air resistance pushes up on the object. Eventually the force gravity exerts down on the object and the force air resistance pushes up on the object become equal, at which point the velocity of the object no longer increases. This is terminal velocity, and it is not the same for every object. The reason it is not the same for every object is because not every object has the same mass or the same amount of surface area or mass distribution. But there is an equation that can describe this: V = sqrt ( (2 * W) / (Cd * r * A) ) Where: D = drag, at terminal velocity D=W Cd = drag coefficient r = the air density V = the square of the air velocity A = some reference area of the object (courtesy of Wilg at HVAC/R engineering http://www.eng-tips.com/viewthread.cfm?qid=83589) To find out more about Newton's Laws and Terminal Velocity, please visit the following: http://www.physicsclassroom.com/Class/newtlaws/U2L3e.html

The fastest you can fall in an atmosphere.

Free falling

The speed of this (*%&% computer when I throw it out the window....