Free Fall Time from 20 meters - How Long to Fall?
Dropping an object from a height of 20 meters in vacuum results in an elapsed fall time of 2.020 seconds and a terminal impact speed of 19.81 m/s (approx. 71.3 km/h or 44.3 mph).
Calculations are derived from classical Newtonian kinematics h = ½gt² under standard Earth gravitational acceleration (g = 9.80665 m/s²).
Free Fall Drop Time & Impact Velocity
Classical Newtonian Kinematics in Vacuum (NIST Reference CODATA)
Elapsed duration for an object to reach ground in vacuum from 20 m.
Drop Time Comparison Across Solar System (20.0m Drop)
t ∝ 1/√gskymotion20-20).Recommended Classical Mechanics & Physics Literature
Hand-selected peer-reviewed literature, optical instruments, and mechanics resources verified by physics educator Traian Anghel.
The Feynman Lectures on Physics, Vol. 1
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Classical Mechanics by John R. Taylor
Clear, rigorous pedagogical treatment of Newton's laws, kinematics, momentum, and orbital mechanics.
Physics for Scientists and Engineers
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20m Drop Time & Weight Across the Solar System
| Celestial Body | Surface Gravity (g) | Fall Duration (t) | Impact Velocity (km/h) | 70kg Person Weight |
|---|---|---|---|---|
Earth | 9.81 m/s² | 2.019 s | 71.3 km/h | 686.7 N (70.0 kg) |
Moon | 1.62 m/s² | 4.969 s | 29.0 km/h | 113.4 N (11.6 kg) |
Mars | 3.71 m/s² | 3.284 s | 43.9 km/h | 259.7 N (26.5 kg) |
Jupiter | 24.79 m/s² | 1.270 s | 113.4 km/h | 1735.3 N (177.0 kg) |
Venus | 8.87 m/s² | 2.124 s | 67.8 km/h | 620.9 N (63.3 kg) |
Mercury | 3.7 m/s² | 3.288 s | 43.8 km/h | 259.0 N (26.4 kg) |
Explore Other Kinematics & Motion Calculators
Frequently Asked Questions
Q1.How long does it take an object to fall 20 meters on Earth?
In a vacuum under standard Earth gravity (g = 9.80665 m/s²), an object dropped from rest takes exactly 2.020 seconds to fall 20 meters, calculated via t = √(2h / g).
Q2.What is the impact velocity from a 20m drop?
At ground impact after falling 20m, the object reaches a velocity of 19.81 m/s, which equals 71.3 km/h (44.3 mph).
Q3.How does free fall from 20m compare on the Moon vs Jupiter?
On the Moon (g = 1.62 m/s²), falling 20m takes 4.97 seconds. On Jupiter (g = 24.79 m/s²), the same fall takes just 1.27 seconds due to its immense gravitational acceleration.
skymotion20-20).Recommended Classical Mechanics & Physics Literature
Hand-selected peer-reviewed literature, optical instruments, and mechanics resources verified by physics educator Traian Anghel.
The Feynman Lectures on Physics, Vol. 1
By Richard Feynman, Robert Leighton & Matthew Sands. Mechanics, radiation, kinetics, and heat.
Classical Mechanics by John R. Taylor
Clear, rigorous pedagogical treatment of Newton's laws, kinematics, momentum, and orbital mechanics.
Physics for Scientists and Engineers
By Raymond A. Serway & John W. Jewett. Comprehensive kinetic energy, work, and friction mechanics.