Buoyancy—the ability of a fluid to exert an upward force on an object immersed in it. 

Two forces act on an object that is in a fluid:

1.  Weight—down

2.  Buoyant force—up

Ø  If weight is greater than BF, it sinks.  Otherwise, it floats. 

 

Archimedes’ Principle—the buoyant force on an object is equal to the weight of the fluid displaced by the object. 

Ø  More volume, more buoyant force!

Ø  Density (mass/volume): an object will float in a fluid if it is less dense than that fluid. 

Pascal’s Principle—Pressure applied to a fluid is felt throughout the fluid

Ø  Pressure—force exerted per unit area (P = F/A)

Ø  hydraulic lifts make use of this principle

o     A large area will have a large force

Bernoulli’s Principle—As the velocity of a fluid increases, the pressure exerted by the fluid decreases

Ø  This is how airplanes fly—air moves faster over the top of the wing, creating a lower pressure—creating lift. 

Viscosity: a fluid’s resistance to flow; determined by molecular structure

·      Increased temperature will lower viscosity (heating = runnier)