Enter a height (in meters) and optionally an initial velocity to calculate the free fall velocity, time of fall, and impact energy of a falling object. You can also provide the object's mass to get the kinetic energy at impact. Based on the standard free fall equations assuming no air resistance and g = 9.8 m/s².
Impact Velocity
--
Impact Velocity (km/h)
--
Time of Fall
--
Kinetic Energy at Impact
--
Verified Fall Distance
--
Free fall is the motion of an object under the influence of gravitational force only, with no other forces — including air resistance — acting on it. In this ideal state, all objects fall with the same constant acceleration regardless of their mass.
On Earth, the acceleration due to gravity is approximately 9.807 m/s². This means that every second an object is in free fall, its velocity increases by about 9.8 m/s. The exact value varies slightly depending on altitude and location.
The velocity of a free-falling object is calculated using the formula v = v₀ + g·t, where v₀ is the initial velocity, g is gravitational acceleration, and t is time. If you know the height h instead of time, you can use v = √(v₀² + 2·g·h).
The height (distance fallen) is given by h = v₀·t + ½·g·t². If the object starts from rest (v₀ = 0), this simplifies to h = ½·g·t². For example, after 2 seconds on Earth, an object falls ½ × 9.807 × 4 ≈ 19.6 meters.
An object dropped from rest on Earth falls approximately 19.6 meters in 2 seconds, using h = ½ × 9.807 × 2² ≈ 19.6 m. It would be moving at about 19.6 m/s (70.6 km/h) at that point.
No — in true free fall (no air resistance), all objects fall at the same rate regardless of their mass. This was famously demonstrated by Galileo and later by Apollo 15 astronauts who dropped a hammer and feather on the Moon simultaneously.
In free fall, the object and everything around it accelerate at the same rate due to gravity, creating a weightless environment. There is no normal force acting on the object, so it experiences apparent weightlessness — the same sensation astronauts feel in orbit.
Free fall assumes no air resistance, so velocity increases indefinitely. Terminal velocity occurs in reality when air resistance equals gravitational force, causing acceleration to stop. For a typical skydiver, terminal velocity is around 53 m/s (190 km/h) in a spread-eagle position.