Two Coins — Flick One, Drop One
Flick one coin off the edge of a table and nudge the other over the side at the same instant, then listen: one click, not two. Whatever the flick, both coins fall through the same height under the same rule, so the floor receives them together — and the strobe ghosts with level lines drawn between them show exactly why.
Cara memakai simulasi ini
- Press Flick! and listen for whether one click or two arrive
- Change the flick speed from a gentle 1.0 m/s to a hard 3.0 m/s and repeat
- Switch between Earth, the Moon, Mars and Jupiter to change g
- Slow the replay to a tenth of real time and read the level lines between the strobe ghosts
Yang perlu diamati
- The two coins are always level with each other at every strobe flash
- Flicking harder sends the coin further out without delaying its landing at all
- Both coins land together on every planet, though the whole fall is slower on the Moon
- The horizontal spacing of the ghosts is even while the vertical spacing grows
- Raising the table delays both landings equally and still produces a single click
Fisika di baliknya
Projectile motion separates into two independent problems sharing one clock. Horizontally there is no force, so the flicked coin keeps a constant velocity and the dropped coin keeps none. Vertically both start with zero vertical velocity and both are acted on by the same g, so both satisfy h = ½gt² and reach the floor at t = √(2h/g). The horizontal velocity appears nowhere in that expression, which is why the size of the flick cannot change the landing time on any planet or from any height.