1
$\begingroup$

Sometimes when i put a wet plate on a flat-solid-slick surface the plate will begin to move after some slight initial rest. what law(s) of physics explains this rare phenomena? is it just hydroplaning?

$\endgroup$
1
  • 1
    $\begingroup$ Please clarify your specific problem or provide additional details to highlight exactly what you need. As it's currently written, it's hard to tell exactly what you're asking. $\endgroup$
    – Community Bot
    Jan 18, 2023 at 18:49

1 Answer 1

0
$\begingroup$

if you place the plate on a wet surface, you trap a cushion of air under it. the water under the plate begins to evaporate into the trapped air, increasing its volume slightly. The expansion lifts the plate just out of solid contact with the countertop but leaves a continuous ring of water all the way around the plate rim, preventing the expanding air from escaping. now the plate is floating almost frictionlessly on the trapped bubble of air and the slightest perturbation will cause the plate to slide sideways.

This principle is used to gently move huge pieces of machinery. Here you place a huge soft rubber cup under the machine and blow air into the space between the cup and the floor. the machine lifts up just until air starts to hiss out the gap between the lip of the cup and the floor, at which time you can push on the machine with your hand and set it to slide like a hockey puck even though it weighs several tons. As long as you keep pumping air into that space, the machine will continue to float on that air cushion and you can easily move it anywhere you want on the floor- even up a ramp and into a truck or onto a fork lift platform.

$\endgroup$
1
  • $\begingroup$ ok, let me get straight. if the table surface is wet and i put a plate on it, then air get trapped between the plate and the surface. the water is pushed outward toward the rim? the plate is gliding b/c air is under it? $\endgroup$
    – blue_ego
    Jan 18, 2023 at 20:38

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.