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Warm – Up Chapter 3-2. 1. How do particle change from a solid to a liquid? 2. What is the difference between evaporation and boiling? 3. What is sublimation? 4. What state of matter is the most common in the universe?. Chapter 3-2 States of Matter. Fluids. Fluids.
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Warm – UpChapter 3-2 • 1. How do particle change from a solid to a liquid? • 2. What is the difference between evaporation and boiling? • 3. What is sublimation? • 4. What state of matter is the most common in the universe?
Chapter 3-2States of Matter Fluids
Fluids • Fluid – nonsolid state of matter • Atoms free to move past each other • Gas or liquid
How do ships float? • Buoyant Force– upward force exerted on an object in a fluid
How do ships float? • If buoyant force < object’s weight, the object will sink.
Pressure • Pressure – amount of force exerted per unit area of a surface • Increases as depth increases • Pressure below is greater than pressure above – upward buoyant force
Archimedes’ Principal • Buoyant force on an object in a fluid is an upward force equal to the weight of the volume of a fluid that the object displaces
Density • Density = mass / volume
Pressure Formula • Pressure = force (N) / area (m2) • SI Unit - pascal
Pascal’s Principal • Hydraulic machines to toothpaste • A fluid in a vessel exerts a pressure of equal intensity in all directions.
Pascal’s Principal • P1 = P2 • F1 = F2 A1 = A2 Cross Multiply! Force is measured in Newton’s (N) Area is in cm2
Calculating Pascal’s Principal • A hydraulic lift is used to lift a heavy machine that is pushing down on a 2.8 m2 piston (A1) with a force (F1) of 3,700 N. What force (F2) needs to be exerted on a 0.072 m2 piston (A2) to lift the machine?
Calculating Pascal’s Principle • In a hydraulic system, a force of 7,500 N is exerted on a piston with an area of 10 m2. If the force exerted on a second piston in the hydraulic system is 1,500 N, what is the area of the second piston?
Fluids in Motion • Fluids move faster in smaller areas compared to larger areas • Viscosity – the resistance of a gas or liquid to flow • High – slow • Low – fast
Bernoulli’s Principle • As the velocity of a fluid increases, the pressure exerted by the fluid decreases.
Flying! • Velocity of the air blown over the top surface of the wing is greater than that of the air below it. • Air pressure pushing down on the top of the wing is lower than the air pressure pushing up on the wing. • Net force below the wing pushes the plane upward.
Try it! • Blow on the top of a sheet of paper.