The physics
Dropped from rest, an object gains the same amount of speed every second, so its speed after t seconds is v = g·t. The distance adds up all the speed gained so far, so it grows with the square of the time: d = ½·g·t².
How deep is a well if a dropped stone takes 2.5 s?
Answer: distance fallen = 30.65 m (speed 24.52 m/s, speed 88.3 km/h).
What we know
- Fall time: 2.5 s
Ignores the time the splash sound takes to come back up.
Step by step
- Given
- t = 2.5 s
- Formula
- d = ½·g·t²
- Substitute
- d = ½ × 9.80665 × 2.5²
- Result
- d = 30.65 m
All results
| Distance fallen | 30.65 m |
|---|---|
| Speed | 24.52 m/s |
| Speed | 88.3 km/h |
Open the free fall from time calculator with these numbers → and change any of them.