Chapter 16: Solids, Liquids, and Gases Section 2: Properties of Fluids Deepest dive record set in 1960, reaching 10.916 m in the Mariana Trench, western Pacific Ocean. Of what material are submarines usually made? Does this material float? What feature of a boat might help it float even when it is made of a material that does not? How might a submersible control its rate of ascent and descent? http://liquidcat.files.wordpress.com/2009/08/bathyscaphe_trieste.jpg

Buoyancy Buoyancy: the ability of a fluid (liquid or gas) to exert an upward force on an object immersed in it An object in a fluid will float if its weight is less than the buoyant force acting on it from the fluid. An object in a fluid will sink if its weight is more than the buoyant force acting on it from the fluid. An object will float if its density is less than the density of the fluid it is placed in. What if the object’s density is more?

Buoyancy Animations http://web.mst.edu/~gbert/Amaster.HTML http://www.youtube.com/watch?v=VDSYXmvjg6M

Archimedes’ Principle Archimedes’ principle: the buoyant force on an object is equal to the weight of the fluid displaced by the object. http://www.youtube.com/watch?v=eQsmq3Hu9HA http://image.tutorvista.com/content/gravitation/buoyancy-archimedes-principle.jpeg

Archimedes’ Principle

Pascal’s Principle Pascal’s principle: the pressure applied to a fluid is transmitted throughout the fluid Pressure is force exerted per unit area. http://www.youtube.com/watch?v=QpmYPeiLUa8 http://www.youtube.com/watch?v=pu3FwgIHsQA&feature=PlayList&p=82AFE6A597CDEDEE&playnext=1&playnext_from=PL&index=24 Hydraulic machines use this principle to lift heavy loads. http://www.youtube.com/watch?v=Zh1bZ_fIEfY

Bernoulli’s Principle Bernoulli’s principle: as the velocity of the fluid increases, the pressure exerted by the fluid decreases. Airplanes use this principle to fly http://www.youtube.com/watch?v=croVrzWn-80

Bernoulli’s Principle http://image.circletrack.com/f/9296472/ctrp_0707_03_z+aerodynamic_downforce+airplane_wing_diagram.jpg

Viscosity Viscosity: a liquid’s resistance to flow. The thicker the liquid, the higher the viscosity. The thinner the liquid, the lower the viscosity Molecular structure determines a fluid’s viscosity Increased temperature will lower viscosity Heat maple syrup and it will become more runny Can you swim faster in water than syrup? Hmm… sounds like a good Mythbusters Episode