IndexWellen, Chaos & MaterieMug

Buoyara

Archimedes’ Principle Physics

\[F_b = \rho_{\text{fluid}}\,V\,g\]
$21.99 USD
$21.99 USD
Sale Ausverkauft
Size

Why does a steel ship float? Buoyara knows. Archimedes’ principle says any body in a fluid feels an upward buoyant force equal to the weight of fluid it displaces, Fb = ρfluid V g. If that beats the body’s weight, as for a hollow hull or a helium balloon, it rises. Pixel-art black ceramic mug in 11 or 15 oz; equation, symbols and sources in the physics panel below.

Shipping calculated at checkout by destinationMade to order, ships in ~10 days

Details

Size & material11oz · 15oz

Black glossy ceramic mug with a C-handle. Lead- and BPA-free.

  • 11oz: 0.33 l
  • 15oz: 0.44 l
CareDishwasher & microwave safe

Dishwasher safe (top rack) or hand wash. Microwave safe.

ShippingBy destination

Shipping calculated at checkout by destination.

Made to order: about 10 days of production and handling before it ships.

Delivery times & where we ship

Returns & replacements21 days

Every item is printed to order, so we can’t accept returns or exchanges for change of mind, or if you ordered the wrong size or colour.

Print defect, misprint, damage or the wrong item? We’ll send a free replacement, or a refund if you prefer. Report it within 21 days of delivery with a photo; no need to send it back.

Full refund & replacement policy

The physics

A body in a fluid is pushed up by a force equal to the weight of the fluid it displaces. If that is more than its own weight it floats, and if less, it sinks.

Buoyara knows exactly how much the water will lift.

Archimedes' principle: a body wholly or partly submerged in a fluid feels an upward force equal to the weight of the fluid it displaces. The formula on this mug computes that weight. The force comes from pressure, which grows with depth, so the water pushes harder on the bottom of an object than on its top.

Whether the object rises depends on the comparison. I RISE ABOVE IT. holds only if the object's average density is less than the fluid's: a block of wood or a helium balloon. A steel ship floats because its hull encloses so much air that its average density is lower than water's; it sinks until the water it displaces weighs as much as the ship. A solid steel bar sinks, though it still seems lighter underwater.

The famous bath and the shout of Eureka are believed to be a later embellishment. The crown problem itself, testing whether a king's crown was pure gold by the water it displaced, is the traditional story behind the principle.

Buoyara does not fight gravity. She lets the fluid do it.

Equations

\[F_b = \rho_{\text{fluid}}\,V\,g\]
SymbolMeaningUnit
\(F_b\) buoyant (upward) force \(\mathrm{N}\)
\(\rho_{\text{fluid}}\) density of the fluid \(\mathrm{kg/m³}\)
\(V\) volume of fluid displaced (the submerged volume) \(\mathrm{m³}\)
\(g\) gravitational acceleration \(\mathrm{m/s²}\)

Sources

  1. Encyclopaedia Britannica — Archimedes’ principle
  2. HyperPhysics — Buoyancy

Source Archimedes (c. 250 BCE). On Floating Bodies, Book I, Propositions 5–7. In The Works of Archimedes, trans. T. L. Heath. Cambridge: Cambridge University Press, 1897.

Field notes

Alle anzeigen
1 3
Alle anzeigen