Enter Free Fall Inputs
Example Data Table
| Scenario | Height | Initial Speed | Gravity | Time to Impact | Impact Speed |
|---|---|---|---|---|---|
| Drop from Rest | 10 m | 0 m/s | 9.8067 m/s² | 1.4281 s | 14.0047 m/s |
| Drop from Rest | 50 m | 0 m/s | 9.8067 m/s² | 3.1933 s | 31.3156 m/s |
| Downward Launch | 30 m | 5 m/s | 9.8067 m/s² | 2.0157 s | 24.7669 m/s |
| Upward Launch | 20 m | 8 m/s | 9.8067 m/s² | 2.9939 s | 21.3604 m/s |
| Moon Drop | 120 m | 0 m/s | 1.6200 m/s² | 12.1716 s | 19.7180 m/s |
Formula Used
h = 1/2 · g · t²t = √(2h / g)v = √(2gh)
h = v₀t + 1/2 · g · t²t = (-v₀ + √(v₀² + 2gh)) / gv = v₀ + gt
0 = h + v₀t - 1/2 · g · t²t = (v₀ + √(v₀² + 2gh)) / gextra rise = v₀² / (2g)
These equations assume constant gravitational acceleration and no air resistance. For tall drops, high drag, or irregular motion, measured data may differ.
How to Use This Calculator
- Select a solve mode that matches the object’s starting motion.
- Choose a gravity preset or switch to custom gravity.
- Enter the starting height and choose meters or feet.
- Add an initial speed for upward or downward launch cases.
- Pick unit preferences, choose decimal places, and submit.
- Review the result cards, full breakdown table, and motion graph, then export the result as CSV or PDF.
Frequently Asked Questions
1) What does this calculator actually compute?
It calculates time to impact for a falling object. It also returns impact speed, average speed, motion direction, selected gravity, and extra rise details when the object starts upward.
2) Does this tool include air resistance?
No. It uses ideal constant-acceleration equations. That works well for many quick estimates, but drag can noticeably increase fall time and reduce impact speed for light or broad objects.
3) When should I use the upward launch mode?
Use it when the object starts above the ground and is thrown upward first. The calculator finds the time to rise, reverse direction, and finally hit the ground.
4) Can I use feet and feet per second?
Yes. Height, speed, and gravity units can be switched independently. The calculator converts everything internally and then reports the final values back in your chosen display units.
5) Why does impact direction always show downward?
Because the reported end state is the moment the object reaches the ground. At that instant, the object is moving downward, even if it began at rest or was launched upward.
6) Can I use Moon, Mars, or a custom gravity value?
Yes. Presets are included for Earth, Moon, Mars, and Jupiter. You can also enter any positive custom gravity value to model other planets, simulations, or classroom problems.
7) What if my initial speed is zero?
That becomes a standard free fall case. You can either use rest mode or leave the speed at zero. Rest mode is cleaner because it automatically applies the simplest equation.
8) What do the CSV and PDF buttons export?
They export the calculated summary shown in the result table. This makes it easy to save project notes, attach calculation outputs, or share classroom examples with others.