Compute fall time and impact speed for an object dropped from a height.
Free fall is the motion of an object under the influence of gravity alone, with no initial vertical velocity and no air resistance. The object accelerates uniformly downward at the local gravitational acceleration g. The distance fallen grows with the square of time, while the speed grows linearly with time.
Enter the height from which the object is dropped and choose the planet. The calculator returns the time taken to reach the ground, t = √(2h/g), and the speed at impact, v = √(2gh). Because mass does not appear, a feather and a hammer fall identically in a vacuum.
In a vacuum, no. Without air resistance all objects fall with the same acceleration regardless of mass, so they hit the ground together.
Real falls in air eventually reach terminal velocity, where drag balances gravity and acceleration stops. This calculator ignores air resistance.