ONLINE FLUID PRESSURE SIMULATOR https phet colorado edusimshtmlunderpressurelatestunderpressureen

ONLINE FLUID PRESSURE SIMULATOR https: //phet. colorado. edu/sims/html/under-pressure/latest/underpressure_en. html

FLUID PRESSURE Ch. 13. 1

PRESSURE v Pressure an – result of a force distributed over area. v The unit of force is the newton (N). v The unit of the area is the square meter

CALCULATING PRESSURE v To calculate pressure, divide the force by the area over which the force acts. v The SI unit of pressure is the pascal (Pa). A pascal is one newton per square meter (N/m^2).

PRESSURE SAMPLE PROBLEM If the area of a box touching the ground is 1. 5 square meters, and its weight is 2700 newtons, what pressure does the box exert on the ground? TIP: Write out the values given to you!

PRESSURE SAMPLE PROBLEM If the area of a box touching the ground is 1. 5 square meters, and its weight is 2700 newtons, what pressure does the box exert on the ground? Area = 1. 5 m^2 Weight (Force) = 2700 N Pressure = Force/Area = 2700 N/1. 5 m^2 = 1800 Pa

PRESSURE IN FLUIDS v How does water pressure change with depth? v Water pressure increases as depth increases. v The pressure in a fluid at any given depth is constant and exerted equally in all directions.

PRESSURE IN FLUIDS v. A fluid is a substance that assumes the shape of its container. v Both liquids and gases are fluids because they both assume the shape of their container.

PRESSURE IN FLUIDS v To determine the pressure exerted by nonmoving fluids we look at two factors: 1. Depth – distance from top or surface of something to its bottom 2. Type of fluid

PRESSURE IN FLUIDS v This is a Pascal vase. Each segment holds a different amount of liquid. How come all the fluid levels are the same? v The levels are the same because the pressure is the same. Pressure depends on depth, not amount.

PRESSURE IN FLUIDS v The amount of fluid measured in terms of volume or weight does not affect pressure. v Diving 6 ft in a pool exerts the same pressure as diving 6 ft in a lake. v The lake has a larger volume of water but that does not affect pressure, since the depth in both cases is the same, the pressure is equal.

PLANETARY ATMOSPHERES v Atmosphere – layer of gases surrounding a planet. v The weight of an atmosphere creates atmospheric pressure at the planet’s surface. v All planets in our solar system have some form of atmosphere.

PLANETARY ATMOSPHERES v Atmospheric pressure is usually measured in Kilo Pascals (k. Pa). v The table on the right gives data about the atmospheric composition and pressure for several planets.

INTERPRETING TABLES v What chemical substance exists in all but one of the atmospheres? Nitrogen v Which planet listed in the table has the greatest atmospheric pressure? What is the value of the pressure? Venus, 9120 k. Pa

CONVERTING UNITS v The bar is another unit of pressure. v 1 bar = 101. 3 k. Pa v The weight of the Earth’s atmosphere exerts a pressure of about 101. 3 k. Pa at sea level.

AIR PRESSURE AND THE ATMOSPHERE v How do you think air pressure changes with altitude? v. Air pressure decreases as the altitude increases. v There is less atmosphere exerting pressure the higher up you get.

AIR PRESSURE AND THE ATMOSPHERE Earth’s atmosphere exerts pressure of about 101 k. Pa at sea level. Why aren't you crushed by air pressure? The pressure inside your body balances the air pressure outside. The balanced forces cancel, resulting in a net force of zero https: //www. youtube. com/watch? v=xg 5 Ni. Owf_Zw