Because of its shape, the clay boat displaces more water than the lump and experiences a greater buoyant force, even though its mass is the same. But if you mold the same lump of clay into the shape of a boat, it will float. If you drop a lump of clay in water, it will sink. This upward force is the force of buoyancy, or simply buoyancy. Therefore a net upward force acts on the body. Since the bottom of the body is at a greater depth than the top of the body, the pressure at the lower part of the body is higher than the pressure at the upper part, as shown in (Figure). In other words, the force due to the pressure at the bottom is pointed up, while at the top, the force due to the pressure is pointed down the forces due to the pressures at the sides are pointing into the body. The force that provides the pressure of a fluid acts on a body perpendicular to the surface of the body. Since this weight is supported by surrounding fluid, the buoyant force must equal the weight of the fluid displaced.Īrchimedes’ principle refers to the force of buoyancy that results when a body is submerged in a fluid, whether partially or wholly. The buoyant force is always present, whether the object floats, sinks, or is suspended in a fluid.įigure 14.21 (a) An object submerged in a fluid experiences a buoyant force. If the buoyant force equals the object’s weight, the object can remain suspended at its present depth. If the buoyant force is less than the object’s weight, the object sinks. If the buoyant force is greater than the object’s weight, the object rises to the surface and floats. There is an upward force, or buoyant force, on any object in any fluid ( (Figure)). This means that the upward force on the bottom of an object in a fluid is greater than the downward force on top of the object. (credit b: modification of work by Allied Navy credit c: modification of work by “Crystl”/Flickr)Īnswers to all these questions, and many others, are based on the fact that pressure increases with depth in a fluid. (c) Helium-filled balloons tug upward on their strings, demonstrating air’s buoyant effect. (b) Submarines have adjustable density (ballast tanks) so that they may float or sink as desired. Figure 14.19 (a) Even objects that sink, like this anchor, are partly supported by water when submerged.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |