AVIATION & AERONAUTIC CALCULATOR
Head Down Speed
A precise tool.
What is the Head Down Speed & How does it work?
Head-down freefall speed is the terminal velocity achieved when an object falls through the air without any significant wind resistance, assuming it has reached a point where its weight is balanced by the drag force.
The formula to calculate head-down freefall speed can be derived from Newton’s second law and the drag equation. For simplicity, we consider the terminal velocity where the net force acting on the object is zero:
v_text{terminal} = sqrt{frac{2mg}{rho A C_d}}
v_text{terminal} = terminal velocity, m = mass of the object, g = acceleration due to gravity, rho = air density, A = cross-sectional area, C_d = drag coefficient
For a typical skydiver, the head-down freefall speed ranges from approximately 160 to 180 miles per hour (mph).
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Frequently Asked Questions
What is head-down freefall speed?
Head-down freefall speed is the maximum constant speed reached by an object falling through the air without wind resistance.
How do I calculate terminal velocity for a skydiver?
Use the formula v_terminal = sqrt((2 * mass * gravity) / (air density * cross-sectional area * drag coefficient)).
What factors affect head-down freefall speed?
Factors include mass, gravity, air density, cross-sectional area of the falling object, and the drag coefficient.
Can I use this calculator for other objects besides skydivers?
Yes, you can calculate head-down freefall speed for any object that falls through the air with similar conditions.
What is terminal velocity in aviation?
Terminal velocity is the constant speed reached by an object when the force of gravity is balanced by the drag force.
How does air density affect freefall speed?
Higher air density increases the drag force, reducing the terminal velocity for a given object.
What is the difference between head-down and head-up freefall speeds?
Head-down freefall speed refers to an object falling with its belly towards the ground, while head-up would be with its back facing down. The calculation assumes no significant wind resistance.
Results are for informational purposes only and do not constitute professional advice.