# WANASAYANSI, nijibuni plz!

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#### Bingley

##### Senior Member
Joined Apr 25, 2011
109 0 0
if warm air rises and cold air descend, why are mountain-tops cooler than the lowlands?

#### Gurta

##### JF-Expert Member
Joined Sep 17, 2010
2,251 69 145
Mimi sio mwanasayansi ila nafikiri when the warm air rises it does not retain its warmth when it reaches the great heights and then there is something to do with atmospheric pressure.

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#### muafaka

##### Senior Member
Joined Oct 30, 2009
101 0 33
Radiation from the sun does not generate heat as it passes through the atmosphere until it hits the earths surface. since air is not a very good conductor of heat, heat is lost with distance away from the earths surface. the mountain top is some distance away from the larger area of the earths surface.

#### King Kong III

##### JF-Expert Member
Joined Oct 15, 2010
31,022 11,965 280
if warm air rises and cold air descend, why are mountain-tops cooler than the lowlands?
Temperature decreases at the rate of 0.6c per every increase of 100m.

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#### Bingley

##### Senior Member
Joined Apr 25, 2011
109 0 0
Radiation from the sun does not generate heat as it passes through the atmosphere until it hits the earths surface. since air is not a very good conductor of heat, heat is lost with distance away from the earths surface. the mountain top is some distance away from the larger area of the earths surface.

...So it means most heat remains on the near surface as air is a poor conductor of heat. While The minimum heat goes higher n then it cools faster!
Now what about density! Isn't warmer air less dense than cool air? Thus, the warmer air will all be forced to move up n leave the cool air beneath it! Though air is a poor conductor of heat?

#### gfsonwin

##### JF-Expert Member
Joined Apr 12, 2012
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Temperature decreases at the rate of 0.6c per every increase of 100m.
did i teach you physics?? you said it correct. ila kwa kuongeza tu as the air rises it does not retain its temperature it adopts the surrounding temp.

#### gfsonwin

##### JF-Expert Member
Joined Apr 12, 2012
17,673 3,547 280
...So it means most heat remains on the near surface as air is a poor conductor of heat. While The minimum heat goes higher n then it cools faster!
Now what about density! Isn't warmer air less dense than cool air? Thus, the warmer air will all be forced to move up n leave the cool air beneath it! Though air is a poor conductor of heat?
do you know anything about diffusion??

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#### Bingley

##### Senior Member
Joined Apr 25, 2011
109 0 0
do you know anything about diffusion??
yes, i do! Can u explain it using diffusion?

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#### Bingley

##### Senior Member
Joined Apr 25, 2011
109 0 0
did i teach you physics?? you said it correct. ila kwa kuongeza tu as the air rises it does not retain its temperature it adopts the surrounding temp.
thank u 4 ur gud answer! But if air adopts the surrounding temp, it means that it will either lose or increase its initial temp in order 4 it to adopt 2 the new surrrounding, ryt?

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#### sugi

##### JF-Expert Member
Joined Feb 12, 2011
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pressure is directly proportional to the temperature,as u go higher the presure decrecreases,so the temperature decreases too!

#### gfsonwin

##### JF-Expert Member
Joined Apr 12, 2012
17,673 3,547 280
thank u 4 ur gud answer! But if air adopts the surrounding temp, it means that it will either lose or increase its initial temp in order 4 it to adopt 2 the new surrrounding, ryt?
yes but the logic behind is the concentration, because the amount of rising air is small compared to the surrounding air

#### Kang

##### JF-Expert Member
Joined Jun 24, 2008
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Hii ni kutokana na mountain tops kuwa na lower pressure kwa sababu ya elevation kubwa i.e kuna hewa ndogo zaidi inakandamiza ukiwa juu zaidi.

Hii inasababisha expansion cooling, hewa ya moto inapopanda juu inaexpand kwa vile pressure ni ndogo na inapoexpand inapoa kwa sababu inatumia joto lake kama energy ya kuiwezesha kuexpand, hii ni process kama inayotokea kwenye friji lako la njumbani compressor inakandamiza gas kisha ile gas inaruhusiwa kuexpand, kuexapnd huku kunasababisha cooling ya kwenye friji kisha gas iliyoexpand inakuwa compressed tena kitu ambacho kunasababisha joto ndo maana friji inatoa joto na mzunguko huo unaendelea.

#### zenmoster

##### JF-Expert Member
Joined Oct 3, 2011
952 4 35
this is explained as follows..... as higher u go as cooler it becomes.. hapa tuna aangalia attitude na sio hewa ya moto wala hewa ya bari.... kila unapo rise kwa height mita 100 centigrade 0.6 hupungua...ukilinganisha na sea level... na ndo maana kwa maeneo ya pwani zote huwa yana joto sana kuliko maeneo yalioko mbali na pwani

#### King Kong III

##### JF-Expert Member
Joined Oct 15, 2010
31,022 11,965 280
did i teach you physics?? you said it correct. ila kwa kuongeza tu as the air rises it does not retain its temperature it adopts the surrounding temp.
Teacher upo fit angle zote naona unatwanga kotekote...

#### Kang

##### JF-Expert Member
Joined Jun 24, 2008
5,307 815 280
did i teach you physics?? you said it correct. ila kwa kuongeza tu as the air rises it does not retain its temperature it adopts the surrounding temp.
It does not adopt its surrounding temperature, it cools because it expands, the act of expansion needs energy so heat energy is used to expand the air thus cooling the air.

#### gfsonwin

##### JF-Expert Member
Joined Apr 12, 2012
17,673 3,547 280
It does not adopt its surrounding temperature, it cools because it expands, the act of expansion needs energy so heat energy is used to expand the air thus cooling the air.
mkuu nashukuru kwa masahihisho haya, ni kweli temp cools as it expands.

#### Chamoto

##### JF-Expert Member
Joined Dec 7, 2007
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if warm air rises and cold air descend, why are mountain-tops cooler than the lowlands?

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#### Bingley

##### Senior Member
Joined Apr 25, 2011
109 0 0
shukrani kwa wote mliojaribu kunifafanulia mpaka nimeanza kuielewa concept. BIG UP sana KANG! Nimekupata vilivyo, Nashukuru!
Gfsonwin asante pia. Pia nimejaribu kuisoma adiabatic cooling kwenye wikipedia na kdg nimeipata, japo ipo a-bit complicated, ila asante chamoto. Asanteni wote.