Experiment associated with Blaise Pascal A long thin tube placed into a barrel Water is poured in the top that increases the Hydrostatic Pressure based on elevation and causes the barrel to burst ID: 776504
Download Presentation The PPT/PDF document " 2.5 Forces in Fluids PASCAL’s Barrel ..." is the property of its rightful owner. Permission is granted to download and print the materials on this web site for personal, non-commercial use only, and to display it on your personal computer provided you do not modify the materials and that you retain all copyright notices contained in the materials. By downloading content from our website, you accept the terms of this agreement.
Slide1
2.5Forces in Fluids
Slide2PASCAL’s Barrel Experiment - 1646
Experiment associated with Blaise PascalA long thin tube placed into a barrel. Water is poured in the top that increases the Hydrostatic Pressure based on elevationand causes the barrel to burst.
Slide3History of Blaise pascal (1623-1662)
French mathematician, physicist, inventor, and writerMathematics1642 – invented one of the first two mechanical calculators (Pascaline)Pascals Triangle – presents Binomial coefficients
Slide4History of Blaise pascal (1623-1662)
Worked in the fields of hydrodynamics, hydrostatics and hydraulic fluidsProposed vacuums were possibleWorked with barometers – showed how pressure changed by taking a barometer to the top of a bell tower in ParisInvented the hydraulic press and the syringe
Slide5PressureThe result of a force distributed over a given area. Equation for Pressure:Pressure = Force / AreaForce = Newton’sArea = m2Units for pressure = Pascal (Pa)
Forces in Fluids
Slide6Example #1Each tile on the bottom of a swimming pool has an area of 0.50 m2. The water above each tile exerts a force of 11,000 N on each tile. How much pressure does the water exert on each tile?
Pressure = Force / AreaPressure = 11,000 N / 0.50 m2Pressure = 22,000 Pascal's
Forces in Fluids
Slide7Example #2The weight of a gallon of milk is about 38 N. If you pour a gallon of milk into a container whose bottom has an area of 0.60 m2, how much pressure will the milk exert on the bottom of the container?
Pressure = Force / AreaPressure = 38 N / 0.60 m2Pressure = 63.33 Pascal's
Forces in Fluids
Slide8Two factors that affect fluid pressure:Depth (Remember Pascals Barrel Experiment)Type of fluid
Forces in Fluids
Slide9Pascal’s PrincipleA change in pressure at any point in a fluid is transmitted equally and unchanged in all directions throughout the fluid.
Forces in Fluids
Slide10What is a hydraulic system?A device that uses pressurized fluid acting on pistons of different sizes to change a force.
Forces in Fluids
Slide11How does a hydraulic system use fluid pressure to do work?An increased output force is produced because a constant pressure is exerted on the larger area of the output piston.
Forces in Fluids
Slide12Forces in Fluids
Example
Slide13Forces in Fluids
Draw this diagram:
Slide14Forces in Fluids
Bernoulli’s Principle
As the speed of a fluid
increases
, the pressure within the fluid
decreases
.
Air always moves from
higher
pressure to
lower
pressure
Slide15Forces in Fluids
How do we use Bernoulli’s principle to make planes fly (Draw diagram)?
Slide1613.1 Assessment
1. What must you know to calculate pressure?
Force and Area
Slide1713.1 Assessment
2. What is the relationship between depth of water and the pressure it exerts?
Water pressure increases as depth increases
Slide1813.1 Assessment
3. How is pressure distributed at a given level in a fluid?
At an given depth, pressure is constant and exerted equally in all directions.
Slide1913.1 Assessment
4. How does the pressure exerted by the atmosphere change as altitude increases?
Pressure decreases as altitude increases
Slide2013.1 Assessment
5. Describe Pascal's Principle
A change in pressure at any point in a fluid is transmitted equally and unchanged in all directions throughout the fluid.
Slide2113.1 Assessment
6. How are fluid speed and fluid pressure related.
As the speed of a fluid increases, the pressure within the fluid decreases.
Slide2213.1 Assessment
7. How does an airplane wing produce lift?
Bernoulli’s Principle:
Air traveling over the top of the wing produces an area of low pressure. High Pressure is below the wing (high pressure goes to low pressure) and produces lift.
Slide2313.1 Assessment
Problem #1:
The weight of the gasoline in a 55 gallon drum creates a force of 1,456 Newton’s. The area of the bottom of the drum is 0.80 m
2
. How much pressure does the gasoline exert on the bottom of the drum?
Slide2413.1 Assessment
Problem #2:
A company makes garden statues by pouring concrete into a mold. The amount used to make a statue if a deer weighs 3,600 N. If the base of the deer statue is 0.60
m
long and 0.40 meters wide, how much pressure will the statue exert on a the ground? (Hint: Area is equal to length times width)
Slide2513.1 Assessment
Problem #3:
A book with a weight of 12 N rests on its back cover. If the books cover measures 0.21
m
by 0.28
m
, how much pressure does the book exert?