Pressue

Pressure is the force pushing down on a surface

Pressure varies with temperature

Fluids and Pressure

A fluid is a substance that can easily flow

Fluid molecules are moving in all directions

All the forces exerted by molecules in a fluid add together to make up the pressure exerted on the fluid

Fluid and Pressure

Fluid pressure increases with depth. The strength of speed for liquid flow depends on

the depth of the origin of flow Water pressure increases as depth increases Water pressure is determined by amount of

water above it and the amount of air pressure above it

Air Pressure

Air pressure results from the weight of air above the molecules at that point.

Air pressure decreases with elevation because higher elevations have less air pressing down on air molecules.

Higher elevations have cooler temperatures because there is less atmosphere to trap the heat.

BuoyancyThe upward force exerted by a fluid on a submerged object

Pascal’s Principle

Fluid exerts pressure on any surface that it touches

With an air mattress you can ignore the rocks and stones beneath you. The air pressure will be distributed equally across the fluid movement of air molecules as they reach across your body. Thanks Pascal!

Pascal Principle

Buoyancy and Density

Substances with the greatest densities are near the bottom of the cup

An object that is more dense that the fluid in which it is submersed will sink. An object that is less dense than the liquid in which it is submersed will float.

ShipsSink or Float

The inside of a ship contains a large column of air

The large column of air reduces the overall density of the ship

The ship will float on water as long as it contains the empty air space near its middle Complete WB pages

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