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Free fall calculator

How long something takes to fall a height and how fast it’s going when it lands, on Earth, the Moon, Mars or Jupiter.

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Time to fall 2.02 s

How it works

t = √(2h ÷ g) · v = g × t

Without air resistance everything falls with the same acceleration g, whatever its weight. The distance fallen grows with the square of the time, h = ½ g t², so the time to fall a height is √(2h ÷ g), and the speed at the bottom is g × t (or √(2gh)). A real feather or skydiver falls slower because of air drag; see the terminal velocity calculator for that.

  1. Time: square root of 2h ÷ g √(2 × 20 m ÷ 9.80665 m/s²) = 2.02 s
  2. Speed: g × t 9.80665 × 2.02 = 19.81 m/s

Good to know

  • Ideal physics: no air resistance, friction or spin unless an input says otherwise.

Printed from rocketcalc.io/physics/free-fall