Choose your worlds, then drop all three balls together.
Ideal free fall: no air resistance, constant gravity, and a hypothetical floor. Ball size is a marker; height measures its downward travel.
Calculated landing results
These predictions use the same model as the animation. A landed ball rests at 0 m/s; impact speed is its speed just before landing.
| World | Gravity (m/s²) | Fall time (s) | Impact speed (m/s) |
|---|
Grab, toss, and bounce
Drag the ball with a mouse, finger, or pen, then release to toss it. Use Reset ball for another drop. This is a bouncing sandbox; use Compare drops for controlled measurements.
Damping is an illustrative engine setting, not the real atmosphere of the selected world. Adjust gravity to make a custom field, including zero gravity.
- Gravity
- 9.80 m/s²
- Speed
- 0.00 m/s
- Bounces
- 0
Choose a world or grab the ball.
How does gravity change a falling object?
With no air resistance, a stronger gravitational field makes the same drop take less time and produces a higher impact speed. Two objects released from rest at the same height in the same field fall together, regardless of mass.
Free-fall formulas and units
For height h in metres and gravity g in metres per second squared:
- Fall time: t = √(2h / g) seconds.
- Impact speed: v = √(2gh) metres per second.
- Before landing: distance fallen is ½gt² and downward speed is gt.
At Earth gravity (9.80 m/s²), a 10-metre drop takes about 1.43 seconds and reaches 14.00 m/s just before landing. Slow motion stretches the animation; the displayed simulation time and predicted results retain the same physical units.
Try these comparisons
- Drop on Earth, the Moon, and Mars from 10 metres. Predict the order before pressing Drop.
- Change the height to 40 metres. The drop is four times higher: does the fall time become four times longer?
- Choose the same world in all three lanes. Their balls should land together.
- Try Saturn, then compare it with Jupiter. These lanes represent gravity fields with an imagined floor.
Pause to inspect height and speed. Reset returns to the release point; Drop starts a new run. Changing a world, height, preset, or playback speed resets the current run. Leaving the tab pauses it; resume when ready. If your device requests reduced motion, playback starts at quarter speed; you can still choose real time.
Sources and model limits
Gravity values are rounded from NASA/JPL planetary physical parameters; the Moon uses the NASA Moon Fact Sheet. The free-fall equations are explained by NASA Glenn's free-falling objects guide.
This is a local, constant-gravity model for short drops, with no atmosphere or terrain in Compare drops. Real gravity varies by location and altitude. Gas and ice giants have no solid surface to stand on; their lanes use reference gravity with a hypothetical floor. Pluto is a dwarf planet, and the Moon is Earth's natural satellite.
The playground uses an approximate collision engine with 40 world units per metre and fixed time steps. Its damping and bouncing are exploratory; they do not model a specific atmosphere or material. Extreme tosses are bounded to keep the ball in view.
Kinetic Particle Flow
Particle Playground