Statics of Fluids Topic

Static Pressure

Concept 6 demos

Side-by-side photos of the buoyancy apparatus in a beaker of water. Left: rubber plate held against the bottom of the hollow cylinder with the cylinder empty. Right: plate has fallen to the bottom of the beaker after filling the cylinder with water.

Buoyancy Apparatus

Demonstrates that buoyancy arises from pressure differences, not from some inherent "lifting force" of water. A plate seals the bottom of a submerged hollow cylinder; it stays attached when only …

Fluid level tube apparatus in a white frame: four connected glass tubes filled with blue-colored water -- one straight wide tube, one with zigzag bends, one spiral, and one S-curve -- all showing water at the same height

Fluid Level Tubes

Connected tubes of different shapes (straight, zigzag, spiral, S-curve) all equilibrate to the same water level, showing that hydrostatic pressure depends only on vertical height, not path geometry.

Four connected glass vessels—narrow tube, Erlenmeyer flask, funnel, and beaker—mounted on a wooden base and connected by red tubing, all filled with red-colored water to the same height

Fluid Level Vessels

Connected vessels of different shapes show that static fluid level depends only on depth, not container geometry. Demonstrates the hydrostatic paradox: containers with vastly different fluid masses exert the same …

Atmospheric Pressure

Concept 7 demos

Intact black 55-gallon drum with vacuum gauge on top, motorized vacuum pump on cart in center, and a previously crushed drum on the right

Collapse of 55-Gallon Drum

Dramatically illustrates the magnitude of atmospheric pressure. A vacuum pump evacuates a sealed 55-gallon steel drum until it catastrophically implodes with a loud bang, crushing on three sides simultaneously. The …

Kirkland coffee can placed upside down on a circular vacuum platform with valve and wooden handle, rubber mallet in foreground, crushed can at right

Coffee Can Crush

Demonstrates the magnitude of atmospheric pressure by evacuating a metal coffee can and then striking it with mallets to initiate buckling. The can leaps off the vacuum platform and collapses …

Red Magdeburg hemispheres with handles and valve fitting, in front of a belt-driven vacuum pump with red hose

Magdeburg Hemispheres

Two evacuated hemispheres cannot be pulled apart by student volunteers, dramatically illustrating that atmospheric pressure exerts enormous force over even modest areas. Challenges the misconception that vacuum "sucks" -- it …

Density and Buoyancy

Concept 12 demos

Welch two-pan balance with two 250 mL beakers: left beaker contains a green-and-white superball, right beaker contains green-dyed water at about 150 mL

Buoyancy Balance

A floating superball displaces exactly its own weight in water, demonstrated directly on a two-pan balance. A bonus step shows that the displaced volume of water weighs the same as …

Three-panel photo: (left) brass bucket and cylinder hanging in air, scale reads ~23 N; (center) cylinder submerged in water, scale reads ~20 N; (right) brass bucket filled with water, scale returns to ~23 N

Archimedes' Principle, Bucket and Cylinder

Quantitative verification of Archimedes' Principle: submerging the brass cylinder reduces the scale reading by the buoyant force, and filling the matched bucket with the displaced water's weight restores the original …

Large dial spring scale (20 N, Sargent-Welch) hanging from horizontal rod on bench clamp stand, with brass crown suspended from the scale in air; Pyrex beaker of water on bench to the right

Archimedes' Principle, Crown

Demonstrates Archimedes' Principle by weighing a brass crown in air and in water. Students calculate the buoyant force and determine the crown's density, connecting to the classic legend of Archimedes …

Siphons, Fountains, Pumps

Concept 4 demos

Four-panel time sequence of Heron's fountain made from three stacked clear plastic containers with purple collar bands, connected by internal tubes. A curved fountain tube exits the top container. Panels show decreasing fountain height as water transfers from middle to bottom chamber.

Heron's Fountain

A three-chamber apparatus demonstrates both siphon and pump action as water translates between vessels. Pouring water into the top chamber compresses air in the bottom chamber, which forces water from …

Glass beaker filled with coiled ball chain sitting at the edge of a gray surface, with the chain end draped over the rim and hanging down

Chain Siphon

A ball chain self-evacuates from a beaker, forming a striking arc above the rim that appears to defy gravity. Demonstrates energy conversion, momentum transfer in linked systems, and the role …

Glass Tantalus cup with visible internal siphon tube standing in a shallow Pyrex dish, next to a 400 mL Pyrex beaker filled with dark colored water

Tantalus Cup

A cup with a hidden internal siphon tube holds water normally until filled past a critical height, then drains completely through the stem. Demonstrates siphon action, threshold behavior, and the …