Question

atmospheric pressure. atmospheric pressure P (in kilopascals, kPa) at altitude h (in kilometers, km) is governed by the formula In (P/Po)=-h/k, where K=7 and Po=100 kPa constants. solve equation of P. use part (a) to find the pressure P at an altitude of 4 km

Answer 1

hi

Answer 2

hi

Answer 3

dont know how to solve it

Answer 4

In (P/Po)=-h/k is given

Answer 5

yes

Answer 6

they also give you Po and k

Answer 7

yes

Answer 8

so

ln(P/100) = -h / 7

Answer 9

k=7 and Po=100 kPa

Answer 10

we want to solve this for P

Answer 11

ok

Answer 12

yes

Answer 13

recall:

ln(a/b) = ln(a) - ln(b)

Answer 14

yes i remember

Answer 15

ln(P) - ln(100) = -h / 7

Answer 16

ln(p) = -h/7 + ln(100)

Answer 17

you added In(100) to both sides?

Answer 18

yes

recall:

\[e ^{\ln(a)}=a\]

Answer 19

yes

Answer 20

whats the next step

Answer 21

ok

Answer 22

\[e ^{\ln(P)} = e ^{(-h/7 + \ln(100))}\]

Answer 23

oh the e value

Answer 24

recall:

\[e ^{a+b} = e ^{a}*e ^{b}\]

Answer 25

\[P = e ^{-h/7} * e ^{\ln(100)}\]

Answer 26

\[P = 100*e ^{-h/7} \]

Answer 27

For h = 4 km, What is P?

Answer 28

you get everything?

Answer 29

oh sorry no

Answer 30

Po=100 kPa

Answer 31

Yes, we want to find P when h = 4 km

Answer 32

we solved for P in terms of h above

Answer 33

oh for part A the book has e^-kh

Answer 34

\[\ln(\frac{ P }{ 100 })=-h/k\]

solving for P,

\[P = 100 * e ^{\frac{ -h }{ 7 }}\]

now you are given h = 4

Answer 35

i need help with another one

Answer 36

\[P = 100 * e ^{\frac{ -4 }{ 7 }}\]

\[P \approx 56.47 kPa\]

Answer 37

i got that answer

Answer 38

k

Answer 39

i have a question

Answer 40

can you open a new thread and tag me please

Answer 41

where u do that

Answer 42

@klogan

Answer 43

yeh it is just type @DanJS