1 P&P 13 States of Matter In this chapter we will combine ideas from the last chapter on thermal physics with the various states of matter. exploration.grc.nasa.gov/.../rocket/state.html exploration.grc.nasa.gov/.../rocket/state.html

2 Assignment 13/3,8,9,26,30,31,34,35,40,42

3 Fluids - liquids and gases Pressure = Force = F N Pascal or Pa Area A m 2 Standard atmosphere = x10 5 Pa 10N/cm 2 or N/m 2

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6 Gas Laws Combined Gas Law 1 – original values 2 – new values P, Pressure, Pa V, Volume, Liter, L T, Temperature, K P 1 V 1 = P 2 V 2 T 1 T 2

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8 Ideal Gas Law PV = n RT P, pressure, Pa V, volume, L n, number of moles or molecules R, universal gas constant: 8.31 Pa m 3 /mol K T, temperature, K

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10 Assignment: 13/3,8,9

11 Pascal’s Principle If an external pressure is applied to a confined fluid, the pressure at every point within the fluid increases by that amount. F 2 F 1 A 2 F 2 F, force, newtons, N A, area, m 2 =

12 calslaw/images/variation_depth.jpg

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14 Buoyant Force F buoyant =  fluid Vg , density for water, 1.00 x 10 3 kg/m 3 v, volume, m 3 g, gravity, 9.8 m/s 2 “The buoyant force on an object is equal to the weight of the fluid displaced by the object, which is equal to the density of the fluid in which the object is immersed multiplied by the object’s volume and the acceleration due to gravity. (page 354)

15 Archimedes’ Principle “An object immersed in a fluid has an upward force on it that is equal to the weight of the fluid displaced by the object. The force does not depend on the weight of the object, only on the weight of the displaced fluid.

16 himedes_files/buoyancy.gif es/buoyancy.jpg

17 P =  h g Pressure at any depth is proportional to the fluid’s weight above that depth. P, pressure, Pascal or N/m 2 , density, kg/m 3 h, depth of object, m As depth increases, psi increases. Also fish change with depth. English psi – pounds per square inch SI unit: Pascal or N/m 2

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21 Buoyant Force & Archimedes 13/26,30,31

22 Bernoulli’s Principle As the velocity of a fluid increases, the pressure exerted by that fluid decreases. solomon.physics.sc.edu/~tedeschi/demo/demo21.html

23 star.tau.ac.il/QUIZ/05/Q07.05.html

24 Solids The thermal expansion of a solid is proportional to the temperature change and original size, and it depends on the material.

25 Coefficient of Linear Expansion,   =  Lchange in length L 1  Torig. length, change in temp Units: 1/ o C or o C -1

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27 Coefficient of Volume Expansion,   =  V change in volume V 1  T orig. volume, change in temp Units: o C -1 Manufacturing many types of glassware made of heat resistant borosilicate glass or soda lime glass using automatic press machines or manual press. Borosilicate Glass(Code: TE-32) with thermal expansion coefficient 32.5X10-7/°C

28 Major Applications Glass trays for Micro oven Transparent roof tiles Glass mixer jars Glass window for automatic washing machines Glass lens and reflector for automotive lighting Glass globes for airport or harbor lighting Colored lenses for railroad signals Fly-eye lens for digital projectors

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