Free Fall Time from 400 meters - How Long to Fall?
Dropping an object from a height of 400 meters in vacuum results in an elapsed fall time of 9.032 seconds and a terminal impact speed of 88.57 m/s (approx. 318.9 km/h or 198.1 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 400 m.
Drop Time Comparison Across Solar System (400.0m 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.
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400m 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 | 9.030 s | 318.9 km/h | 686.7 N (70.0 kg) |
Moon | 1.62 m/s² | 22.222 s | 129.6 km/h | 113.4 N (11.6 kg) |
Mars | 3.71 m/s² | 14.684 s | 196.1 km/h | 259.7 N (26.5 kg) |
Jupiter | 24.79 m/s² | 5.681 s | 507.0 km/h | 1735.3 N (177.0 kg) |
Venus | 8.87 m/s² | 9.497 s | 303.3 km/h | 620.9 N (63.3 kg) |
Mercury | 3.7 m/s² | 14.704 s | 195.9 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 400 meters on Earth?
In a vacuum under standard Earth gravity (g = 9.80665 m/s²), an object dropped from rest takes exactly 9.032 seconds to fall 400 meters, calculated via t = √(2h / g).
Q2.What is the impact velocity from a 400m drop?
At ground impact after falling 400m, the object reaches a velocity of 88.57 m/s, which equals 318.9 km/h (198.1 mph).
Q3.How does free fall from 400m compare on the Moon vs Jupiter?
On the Moon (g = 1.62 m/s²), falling 400m takes 22.22 seconds. On Jupiter (g = 24.79 m/s²), the same fall takes just 5.68 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.