Properties of Fluids

1. Definition of Buoyancy

2. Buoyancy A fluid, liquid or gas, that exerts an upward force on an object immersed in it. If buoyant force is equal to or greater than the object’s weight; object floats. If buoyant force is less than object’s weight, the object will sink.

3.Archimedes’ Principle The buoyant force on an object is equal to the weight of the fluid displaced by the object. If you place an object in water, it will displace the water and begin to sink. (a) when the weight of the water displaced equals the object’s weight, the object will float (b) if the weight of the water displace is less than the weight of the object, the object sinks

4.Archimedes’ Principle

5. Density Recall, density is the mass per unit volume. An object will float if its density is less than the density of the fluid it is placed in.

6. Pascal’s Principle Pressure is force exerted per unit area Example: when you squeeze one end of a toothpaste tube, toothpaste expands out the other end (Problems)

Pascal’s

7. Bernoulli’s Principle What is it? Bernoulli's Principle is a law of physics that has to do with gasses (such as air) and liquids (like water). It states that when the velocity (speed) of a gas or liquid is increased, its pressure becomes lower. Give me an example! When air rushes over the curved top of an aircraft wing, it goes faster than when it passes over the flat bottom of the wing. Therefore, the pressure or force of the air pressing down on the top of the wing becomes less than the force of the air pressing up on the bottom of the wing. The result is lift, one of the Four Forces of Flight.

7. Bernoulli’s Principle Pressure decreases as velocity increases Pressure increases as velocity decreases

8. Viscosity Resistance to flow by a fluid Low viscosity = flows easily High viscosity = flows slowly Effected by structure (high viscosity..low flow…if particles do not pull other particles into motion) and temperature (heated…flow easily…low viscosity)