Drop a ball from a 100 m tower on the Moon, click at every red flash,
and recover the lunar gravity g from your own reaction time.
Stopwatch0.00s
Click anywhere on the scene to drop the ball
and start the clock.
Marks recorded0 / 20
Next mark5 m
Tip: 1.0× keeps your reaction-time noise honest.
#
x (m)
your t (s)
true t (s)
Δt
Results: time vs. distance
Estimated g (from your clicks)–
True lunar g1.625 m/s²
Mean reaction delay–
Each point is one click (a red-mark flash). The curve is the physics:
x = ½ gt². The gap between your
points and the curve is your reaction time — the measurement error you
will model back in R.