Transcript Chapter 11Section 1 - Toll Middle School

Chapter 11 Section 1
Forces in Fluid
What is Pressure?
• Pressure is a type of force exerted over an
area.
• Pressure and Area; the larger the area
over which the force is distributed, the less
pressure is exerted.
• Calculating Pressure: Pressure =Force
Area
Unit for Pressure is Pascal (Pa)=1N/m2
Problem solving
• 1. Who exerts more pressure on the ground a
500N woman standing on high heels with a total
area of 0.005 m2, or the same woman standing
in work boots with total area of 0.05m2 Calculate
the pressure she exerts on the ground in both
cases.
• The woman standing in high heels exert more
pressure because the force is exerted over a
small area. 100,000Pa , 10,000Pa
What is Fluid Pressure?
• Fluid particles constantly move, as they
move, they collide against each other and
against the walls of the container.
• In a fluid, all of the forces exerted by
individual particles combine to make up
the pressure exerted by the fluid.
• Air Pressure Air exerts a pressure
because it has mass, each cubic meter air
around you has mass of about 1 kilogram.
• Atmospheric pressure, is air pressure
caused by the weight of air.
What is Balanced Pressure?
• Balanced Pressure Fluid pressure at a
given point is exerted equally in all
directions. The pressures balance each
other out.
• The reason that air pressure does not
crush us is because of balanced pressure,
our body has fluids and those fluids exert
a reaction force into the air.
Variations in Fluid Pressure
• Atmospheric pressure decreases as your
elevation increases.
• Water pressure increases as depth
increases.
• Measuring Pressure The instrument used
to measure the atmospheric pressure is
known as barometer.
• Atmospheric pressure at sea level is
101,000Pa or 760 millimeters of mercury
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Do numbers 1 a
#2 a,b
#3 a,b,c