Terminal Velocity

[Jmacp]

i have this equation for terminal velocity , situation is an object free falling from a height and taking air resistace into account.

TerminalVelocity = Sqr((2 * dblMass * GravityConstant) / (DragCoefficient * AirDensity * FrontalArea(dblRadius)))

so you can take out dblMass , GravityConstant, DragCoefficient and FrontalArea as these things never change for a given situation, which leaves you with approx,


TerminalVelocity = 1 / sqr(AirDensity)

if the air density is always increasing how can you hit a terminal velocity
any thoughts?

[zaza]

I suspect that this is an equation for the coefficient when calculating terminal velocity.

F = k v^2, where k is the coefficient and F is the resistive force on the falling object. It increases as the square of the velocity. The velocity will keep increasing until F is equal to the gravitational force. Then there is no longer a net force on the object, so it moves at constant velocity.

Edit: Incidentally, strictly one would say that F = -kv^2 because the force is in the opposite direction to the velocity.

zaza