{"id":116,"date":"2015-07-29T15:24:06","date_gmt":"2015-07-29T22:24:06","guid":{"rendered":"http:\/\/hub.wsu.edu\/physdemos\/?page_id=116"},"modified":"2026-03-16T15:57:14","modified_gmt":"2026-03-16T22:57:14","slug":"fluid-mechanics","status":"publish","type":"page","link":"https:\/\/hub.wsu.edu\/physdemos\/fluid-mechanics\/","title":{"rendered":"Fluid Mechanics"},"content":{"rendered":"
\r\n\t\nHub Network Sites<\/span><\/a><\/span> > Physics Demonstrations<\/span><\/a><\/span> > Physics Demonstrations<\/span><\/a><\/span> > Recent Visitors<\/span><\/a><\/span><\/div>
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\r\n\t\tFluid Mechanics\t<\/h1>\r\n\t\t<\/header>\r\n\n\n
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Surface Tension<\/h2>\n\n\n\n

Submerged Float<\/h3>\n\n\n\n

PIRA<\/b>: 2A10.15<\/p>\n\n\n\n

Description<\/b>: A ring with a large cork stopper attached is weighted so that it will float with the ring above the surface. When the ring is forced below the surface, it cannot rise above the surface due to surface tension.<\/p>\n\n\n\n

Needle Float<\/h3>\n\n\n\n

PIRA<\/b>: 2A10.20<\/p>\n\n\n\n

Description<\/b>: The surface tension of water is sufficient to float a slightly greasy sewing needle, skin oil will work.<\/p>\n\n\n\n

Floating Strawberry Basket<\/h3>\n\n\n\n

PIRA<\/b>: 2A10.22<\/p>\n\n\n\n

Description<\/b>: Even though strawberry baskets are more dense than water they will float because of surface tension. They will sink if they are wet and will not float again until they are completely dry.<\/p>\n\n\n\n

Plate Measure of Surface Tension<\/h3>\n\n\n\n

PIRA<\/b>: 2A10.33<\/p>\n\n\n\n

Description<\/b>: A round plate is lifted by a rubber band, and the rubber band stretches to a certain length. When the round plate is placed on the surface of water and lifted again, the rubber band will stretch more.<\/p>\n\n\n\n

Bubble Makers<\/h3>\n\n\n\n

PIRA<\/b>: 2A10.52<\/p>\n\n\n\n

Description<\/b>: A set of bubble makers to demonstrate surface tension, and discuss why bubbles are always round.<\/p>\n\n\n\n

Double Bubble Paradox<\/h3>\n\n\n\n

PIRA<\/b>: 2A10.53<\/p>\n\n\n\n

Description<\/b>: Two bubbles are blown, one should be larger than the other. When the two are connected together, the larger bubble will get even larger. This is due to surface tension.<\/p>\n\n\n\n

Capillary Tubes<\/h3>\n\n\n\n

PIRA<\/b>: 2A20.10<\/p>\n\n\n\n

Description<\/b>: Show the rise of water in a small diameter tube due to surface tension.<\/p>\n\n\n\n

Statics of Fluids<\/h2>\n\n\n\n

Pressure Independent of Direction<\/h3>\n\n\n\n

PIRA<\/b>: 2B20.10<\/p>\n\n\n\n

Description<\/b>: Thistle tubes connected to a U-tube manometer are used to determine the pressure at depth in a fluid. The thistle tube point both downward and sideways. Direction of the pressure can be discussed as one thistle tube points downward and the other points to the side.<\/p>\n\n\n\n

Pascal’s Vessels<\/h3>\n\n\n\n

PIRA<\/b>: 2B20.40<\/p>\n\n\n\n

Description<\/b>: These variously shaped tubes are used to show that water seeks its own level. The height of the fluid in the column depends only on the pressure to which it is exposed and not on the diameter of the column.<\/p>\n\n\n\n

Hydraulic Press<\/h3>\n\n\n\n

PIRA<\/b>: 2B20.60<\/p>\n\n\n\n

Description<\/b>: The hydraulic jack can be used to break scrap pieces of wood, showing that the force on the small cylinder is multiplied to achieve the larger force on the large cylinder.<\/p>\n\n\n\n

Bed of Nails<\/h3>\n\n\n\n