Free Fall Lab (2D) | mysimulator.uk

Drop Setup

Drop height 18 m

Mass 1.0 kg

Cross-section area 0.05 m²

Air Resistance

Set the height and mass, then drop.

Live Readout

Vacuum: t

0.00 s

Vacuum: v

0.0 m/s

Air: t

0.00 s

Air: v

0.0 m/s

Theoretical v_term

– m/s

Height fallen

0.0 m

How it works

In a vacuum every falling object obeys the same two equations regardless of mass: velocity v = g·t and distance fallen h = ½·g·t², with g = 9.8 m/s². That is why a coin and a boulder released together always land at the same instant when air is removed.

With air resistance, drag grows with the square of speed: F_drag = ½·ρ·C_d·A·v², opposing gravity. As the object speeds up, drag grows until it exactly balances weight (m·g), and the object stops accelerating — that speed is the terminal velocity, v_term = √(2·m·g / (ρ·C_d·A)). Heavier, denser, more compact objects (high mass, small area) reach a higher terminal velocity and keep accelerating longer; light, wide objects (low mass, large area) reach a low terminal velocity almost immediately.

Use the mass and cross-section sliders to see how the two competing factors — weight pulling down, drag pushing back — change the shape of the fall, and switch on "Compare with air" to race the drag-affected drop against the ideal vacuum drop side by side.

Vacuum (g only) With air resistance