🪂 Terminal Velocity: When Drag Finally Catches Gravity

About this simulation

A falling body speeds up because gravity pulls it down with a constant force, Fg = m·g. But as it accelerates, air drag pushes back harder — drag grows with the square of speed: Fd = ½·Cd·ρ·A·v². Eventually the two forces are equal and opposite, net acceleration drops to zero, and the object stops speeding up. That steady speed is the terminal velocity.

How it works

• Mass (m) — heavier objects need more drag force to balance their weight, so they reach a higher terminal velocity.
• Cross-section area (A) and drag coefficient (Cd) — a wider or bluffer shape catches more air, increasing drag and lowering terminal velocity.
• Air density (ρ) — thinner air (like high altitude) produces less drag, so terminal velocity rises; denser air lowers it.
• The red arrow shows constant gravity; the orange arrow shows drag growing with v² until it matches gravity in length.

Controls

• Mass — the falling object's mass in kilograms.
• Body orientation — a shape/pose preset that sets the drag coefficient, modelled loosely on real skydiving postures.
• Cross-section area — the frontal area presented to the airflow.
• Air density — density of the fluid being fallen through (sea-level air ≈ 1.23 kg/m³).
• ↺ Drop again — resets the fall from height zero. Drag to rotate, scroll to zoom.

Did you know?

A skydiver belly-to-earth reaches roughly 55 m/s (200 km/h), but flipping head-down into a dive shrinks the cross-section and drag coefficient enough to push terminal velocity past 90 m/s (325 km/h) — which is exactly why speed skydivers dive head-first.