Physics
Gravity
Drop a feather and a hammer in vacuum, on Earth, the Moon or Mars — and see why heavy objects don't fall faster.
World
g = 9.81 m/s² · no air
Stats
- Time
- 0.00s
- Gravity
- 9.81 m/s²
- v feather
- 0.0 m/s
- v hammer
- 0.0 m/s
In a vacuum or on the Moon (no atmosphere) the feather and the hammer land at the same time. Add air, and the feather lags. Apollo 15's David Scott did this on live TV in 1971.
Every mass attracts every other mass. On Earth's surface, gravity pulls things downward at about 9.8 m/s² — meaning each second, a falling object's downward speed increases by 9.8 m/s.
Weight
W = m × g
g ≈ 9.8 m/s² on Earth
Newton's law of gravitation
F = G · m₁m₂ / r²
In a vacuum, a feather and a hammer fall at the same rate. The Apollo 15 astronauts demonstrated this on the Moon.