Pressure
Force exerted on a surface divided by the total area over which the force is exerted.
Pascal
The SI unit of pressure.
Fluid
A material that can flow easily.
Barometer
An instrument that can measure atmospheric pressure.
Buoyant Force
The upward force exerted by a fluid on a submerged object.
Archimedes' Principle
States that the buoyant force on an object is equal to the weight of the fluid displaced by the object.
Density
Mass per unit volume. Mass/Volume
Pascal's Principle
When force is applied to confined fluid, the change in pressure is transmitted equally to all parts of the fluid.
Hydraulic System
A system that multiplies force by applying the force to a small surface area. The increase in pressure is then transmitted to another part of the confined fluid, which pushes on a larger surface area.
Bernoulli's Principle
The faster a fluid moves, the more its pressure decreases.
Lift
An upward force.
Describe how molecules move in fluids
They move constantly in all directiongs
What causes the pressure exerted by a fluid?
all the forces exerted by the individual particles in a fluid combine to make up the pressure exerted by the fluid
1N/m2 ='s what?
1Pa
what 2 factors does pressure depend on?
force and area; pressure = force/area
how does atmospheric pressure change as you move away from the surface of the earth?
as elevation increases, atmospheric pressure decreases
does water pressure increase or decrease as depth increases?
increases
What is the mathematical relationship b/w force, pressure and area?
P = Force/Area
what causes pressure in fluids?
moving particles in the fluid collide
Density
mass/volume
How does the buoyant force work?
it acts in the direction opposite to the force of gravity, so it makes an object feel lighter
according to bernoulli's principle, how is fluid pressure related to the motion of a fluid?
according to bernoulli's principle as the speed of a moving fluid increases, the pressure within the fluid decreases.
how does a hydraulic device multiply force?
a hydraulic system multiplies force by applying the force to a small surface area. the increase in pressure is then transmitted to another part of the confined fluid, which pushes on a larger surface area.
chimneys and bernoulli's principle...why does the smoke rise?
it rises up the chimney partly b/c hot air rises and partly b/c it is pushed. Wind blowing across the top of a chimney lowers the air pressure there. the higher pressure at the bottom pushes air and smoke up the chimney. smoke will rise faster in a chimne
list 4 applications of bernoulli's principle
objects in flight
atomizers
chimneys
flying discs
how can you predict whether an object will float or sink?
by comparing densities