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touqra
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Why is it that you feel cold on the mountains when you are actually nearer to the Sun? By right, it should be hotter.
russ_watters said:Because you aren't that much nearer to the sun - what's a few thousand feet compared to 90 million miles? There are a number of reasons why it is cooler at higher altitudes, but the main one is that as warm air rises and the pressure drops (because there is less air above pushing down), the air expands and cools according to the ideal gas law.
Boyle's Law, [tex] P_1V_1 = P_2V_2 [/tex] assumes that temperature is held constant. You can't use that here.touqra said:The temperature of air is dependent on its internal energy and not on the volume expansion. If quoting, PV = nRT, we have, [tex] P_1V_1 = P_2V_2 [/tex]. The temperature does not change, no?
Further, when the warm air rises and cools, shouldn't it "drop down" to a lower altitude?
If the air cools down when it rises to a higher altitude, the energy lost must go somewhere but where?
...and thus requires heat transfer.FredGarvin said:Boyle's Law, assumes that temperature is held constant.
Yes, it does sometimes set up a convection, but regardless, it will still be warmer lower and cooler higher except in rare cases of a temperature inversion. Ie, you can't have convection unless it is warmer lower and cooler higher.touqra said:Further, when the warm air rises and cools, shouldn't it "drop down" to a lower altitude?
FredGarvin said:Boyle's Law, [tex] P_1V_1 = P_2V_2 [/tex] assumes that temperature is held constant. You can't use that here.
Think of it this way, as altitude increases, pressure decreases. If pressure decreases, the interaction between molecules, i.e. collisions will be less. An expanding gas cools. If you don't believe this, look at a standard altitude chart here and notice the temperature distribution with altitude.
http://www.pdas.com/e2.htm
http://aero.stanford.edu/StdAtm.html
Here is a nice reference on the computations:
http://www.pdas.com/hydro.pdf
touqra said:If the expanding gas does cools, where has the heat energy transferred to?
touqra said:An expanding gas cools because it did work. I can't imagine what the air is doing work unto.
The average temperature on a mountain can vary greatly depending on the elevation, time of day, and season. However, on average, the temperature decreases by approximately 3.6 degrees Fahrenheit for every 1,000 feet of elevation gain.
The temperature on a mountain decreases as you go higher due to a decrease in air pressure. As altitude increases, the air becomes less dense and is therefore unable to hold as much heat, resulting in lower temperatures.
Yes, the temperature on a mountain is typically lower than the temperature at sea level. This is because as elevation increases, the air becomes thinner and is unable to trap heat as efficiently, resulting in lower temperatures.
The temperature on a mountain can greatly impact the plant and animal life that inhabit it. As temperatures decrease with elevation, different species are able to thrive in different temperature ranges. This can result in unique and diverse ecosystems on different parts of the mountain.
Yes, the temperature on a mountain can change quickly and drastically. This is due to various factors such as changes in elevation, weather patterns, and time of day. It is important for those planning to climb a mountain to be prepared for sudden changes in temperature by bringing appropriate clothing and gear.