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Pressure vs Altitude Relationship

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					press_alt.mcd                                                                                   1/18/98

Pressure vs Altitude relatioships
by S.E. Van Bramer, 1/18/98



   The relationship:
                            M. g. ht
                           R . T sea
             P ht P o. e



   The variables:


           The atmospheric pressure at sea level            Po      101325. Pa

                                                                                         1
           The average molecular mass of the atmosphere:    M       0.02897 . kg. mole

                                                                                         3
           The altitude of interest (given as a matrix)     ht   0 . m , 20. m .. 100. 10 . m

                                                            T sea      288. K
           The average temperature at seal level
                                                                                   1             1
           The gas law constant:                            R    8.314510. joule. K . mole


     The function:

                                                 M. g. ht
                                                R . T sea
                            P( ht )    P o. e
press_alt.mcd                                                                                1/18/98

      The graph:


                                                 Pressure Altitude Relationship
                            1.2 105



                              1 105



                                  4
                              8 10
      Pressure (Pa)




                      P( ht )
                       Pa 6 104




                              4 104



                                  4
                              2 10



                                    0
                                        0   20        40                   60     80   100
                                                                 ht
                                                                km
                                                           Altitude (km)




                                                 Pressure Altitude Relationship
                                   12



                                   10



                                    8
      ln (Pressure)




                                    6
                      ln P( ht )
                          Pa

                                    4



                                    2



                                    0



                                    2
                                        0   20        40                   60     80    100
                                                                 ht
                                                                km
                                                           Altitude (km)

				
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