10-5 Measurement of Pressure;Gauges and the Barometer•Ptot = Po + rgh•Gauges and measuring devices that measure pressure often compare the pressure of a contained space to that of the atmosphere.•See page 280 diagrams•A mercury barometer uses the height of a column of mercury to measure atmospheric pressure.•A manometer does much the same, but with a sealed container for vapor pressure.

• rgh=(13.6 x 103 kg/m3 ) (9.80 m/s2 )(1.00x10-3 m)• …so 1mm Hg = 133 N/m2

• 1 torr = 1 mmHg (Evangelista Torriceli 1608-1647)

10-6 Buoyancy and Archimedes's Principle

• The story of Archimedes….• Meanwhile, back in physics…• Fb = rf gV• Archimedes’ principle…the buoyant force on a

body immersed in a fluid is equal to the weight of the fluid displaced by that object.

• See example 10-5 and Holt example 9- • See example 10-6 and 10-9 Giancoli.

Homework

• Giancoli p 304 pr#12-#15 and #21-#24 due Monday BOP