Day 41

Investigation 8 part 1Air Pressure Inquiry

Arrows

Visualization Exercise 8.1

Resources, P. 49

Labels and Connection to text

Visualization Exercise 8.2

Resources, P. 50

Resources, P. 50

Reading

• Starting on page 48 of your resource book read “What is Air Pressure”

• Answer the “Think Questions” on page 52.

Barometer

• Measures air pressure

• Baro- means pressure

• -meter- means measure

Aneroid Barometer

• How does an aneroid barometer work?–As pressure changes, a spring will coil and uncoil

and give us a reading in millibars

• What is the advantage?–Small and compact

Mercury Barometer

• Long glass tube filled with mercury, placed in a dish of mercury

• Force of air on the surface of mercury pushes the column of mercury up the tube

• Although mercury is very toxic, what is the advantage?– Very accurate

Units• Bars

– Used to measure air pressure– Equal to the pressure exerted by air

in the atmosphere at sea level

• Millibar (mb)– Unit used to measure atmospheric

pressure– 1/1000 of a bar– average sea-level air pressure = 1013

mb

Response Sheet-Air Pressure and Wind

• Pull out page 47 of your lab book and answer the question.