An egg balances on a tube, on a tray, on top of a glass of water. If you flick the tray away just right, the egg drops straight down into the glass instead of falling off the table. Use the simulator below to find out how hard you really have to hit it — and why the egg doesn't break when it lands.
Newton's First Law says an object at rest stays at rest unless a force pushes it. The egg "wants" to stay right where it is — it has no reason to move sideways on its own.
While the tray is still sliding underneath the tube, friction between them tries to drag the egg along. This is the only force that can pull the egg sideways.
The tray pushes up on the tube to hold the egg up. The instant the tray is gone, that support disappears — and the egg has nothing left holding it up.
Once the tray clears out, gravity is the only big force left. It pulls the egg straight down, into the glass if it hasn't picked up much sideways speed.
A harder hit sends the tray out faster, so it clears the tube in less time. Less contact time means friction barely has a chance to drag the egg — that's the whole trick!
Even a "safe" landing means the egg is falling at about the same speed either way — the difference is how long it takes to stop. Stopping over a longer time and distance means a much smaller force, and that's exactly what water does.
Water lets the egg slow down gently over about 5 cm. A longer stopping distance means a small, gentle stopping force.
A hard table stops the egg almost instantly, in about 1 mm. A much shorter stopping distance means a huge, sudden force — more than the shell can handle.
Bonus fact: once the egg is underwater, the water also pushes up on it a little (this push is called buoyant force), slowing it down even more before it can hit the bottom of the glass.