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Physics Quiz Question
Brought over from RAS:
Assuming that all other variables remain constant: An increase in temperature will result in a higher atmospheric pressure - a higher temperature speeds up the movement of the air molecules, thereby raising the pressure they exert on the surrounding atmosphere. A) True B) False -- Dallas |
#2
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Physics Quiz Question
In a previous article, said:
Brought over from RAS: Assuming that all other variables remain constant: An increase in temperature will result in a higher atmospheric pressure - a higher temperature speeds up the movement of the air molecules, thereby raising the pressure they exert on the surrounding atmosphere. A) True B) False That would be true if the atmosphere was a closed container. It's not, it's free to expand, so the pressure does not rise. -- Paul Tomblin http://blog.xcski.com/ Never underestimate the bandwidth of a station wagon full of tapes hurtling down the highway. -- Andrew Tannenbaum possibly quoting Warren Jackson |
#3
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Physics Quiz Question
(Paul Tomblin) wrote:
In a previous article, said: Brought over from RAS: Assuming that all other variables remain constant: An increase in temperature will result in a higher atmospheric pressure - a higher temperature speeds up the movement of the air molecules, thereby raising the pressure they exert on the surrounding atmosphere. A) True B) False That would be true if the atmosphere was a closed container. It's not, it's free to expand, so the pressure does not rise. I think you are right, but is it a trick question? He said "all other variables remain constant" Does that include the volume of the atmosphere? Never mind that such an assumption makes no sense. -- Alex -- Replace "nospam" with "mail" to reply by email. Checked infrequently. |
#4
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Physics Quiz Question
On Mon, 06 Aug 2007 14:34:07 -0400, alexy wrote:
I think you are right, but is it a trick question? It's not supposed to be a tricky question. I posted it because everyone seems to have a different answer for it. It's a tiny bit like the old "airplane on a treadmill" debate. -- Dallas |
#5
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Physics Quiz Question
On Aug 6, 1:05 pm, Dallas wrote:
Brought over from RAS: Assuming that all other variables remain constant: An increase in temperature will result in a higher atmospheric pressure - a higher temperature speeds up the movement of the air molecules, thereby raising the pressure they exert on the surrounding atmosphere. A) True B) False Well, the answer is false but it is a rather bogus problem, mainly because the atmosphere is not fully contained; in other words, the volume CAN change. The way this is worded, the fluid (atmospheric gas) is also being used as the container. Pressure is a measurement of normal (perpendicular) force against a surface, you can't have a pressure without a surface against which an equal and opposite pressure can be exerted. Since the atmosphere can expand (because it is not closed), it doesn't have anything to exert pressure against EXCEPT for the earth's surface. But I invite you to think about: Of what is a temperature a measurement, how does force relate to potential energy and mass, how pressure relates to force and mass, how potential and kinetic energy is related, how kinetic energy is related to velocity, what the laws of conservation of energy entail, and what "atmospheric pressure" is). Hint: "atmospheric pressure" is a measurement of the pressure of the air due to the acceleration of gravity on the mass of column of air directly above it, not as a measure of pressure against the "surrounding" atmosphere. |
#6
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Physics Quiz Question
"Dallas" wrote in message
... Brought over from RAS: Assuming that all other variables remain constant: An increase in temperature will result in a higher atmospheric pressure - a higher temperature speeds up the movement of the air molecules, thereby raising the pressure they exert on the surrounding atmosphere. A) True B) False False and/or True. The air can expand. If it expands vertically, the pressure is unchanged. If it expands horizantally, the pressure goes down. If the air is constrained, the pressure goes up. Depends on what you mean by "all other variables remain constant" PV = nRT -- Geoff The Sea Hawk at Wow Way d0t Com remove spaces and make the obvious substitutions to reply by mail When immigration is outlawed, only outlaws will immigrate. |
#7
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Physics Quiz Question
the variable that matters is that there's 14.7 pounds of air over
every square inch at sea level. If that's the one that stays constant, the answer is clear. On Aug 6, 3:00 pm, "Capt. Geoffrey Thorpe" The Sea Hawk at wow way d0t com wrote: "Dallas" wrote in message ... Brought over from RAS: Assuming that all other variables remain constant: An increase in temperature will result in a higher atmospheric pressure - a higher temperature speeds up the movement of the air molecules, thereby raising the pressure they exert on the surrounding atmosphere. A) True B) False False and/or True. The air can expand. If it expands vertically, the pressure is unchanged. If it expands horizantally, the pressure goes down. If the air is constrained, the pressure goes up. Depends on what you mean by "all other variables remain constant" PV = nRT -- Geoff The Sea Hawk at Wow Way d0t Com remove spaces and make the obvious substitutions to reply by mail When immigration is outlawed, only outlaws will immigrate. |
#8
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Physics Quiz Question
On Aug 6, 9:37 pm, Tina wrote:
the variable that matters is that there's 14.7 pounds of air over every square inch at sea level. If that's the one that stays constant, the answer is clear. Well...not to quibble, but 14.7 (ok, 14.694) psi is the MEAN sea level pressure. There are localized variations in pressure caused by density differences over those areas. (which is why GENERALLY speaking, areas of lower pressure indicate "rain" systems; the lighter air indicates a higher moisture content). Although, in large enough volumes the differences are close enough to zero that they do not significantly affect calculations since lim (m/V) = 0 V-inf |
#9
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Physics Quiz Question
On Aug 7, 3:05 am, Dallas wrote:
Brought over from RAS: Assuming that all other variables remain constant: An increase in temperature will result in a higher atmospheric pressure - a higher temperature speeds up the movement of the air molecules, thereby raising the pressure they exert on the surrounding atmosphere. A) True B) False -- The answer is true, but the usefulness of the question is doubtfall because all things dont remain constant. In practice , at least where I live, the temperature can change quite radily during the day with virtually no change in pressure. But then when you talk about synoptic charts, high pressure is associated with higher temperatures, and vice versa for low pressure systems. terry |
#10
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Physics Quiz Question
On Mon, 6 Aug 2007 12:05:17 -0500, Dallas wrote:
An increase in temperature will result in a higher atmospheric pressure - a higher temperature speeds up the movement of the air molecules, thereby raising the pressure they exert on the surrounding atmosphere. A) True B) False The origin of the question comes from the current edition of the Jeppesen Private Pilot manual. Here's the exact text: http://img.photobucket.com/albums/v1...allas/Jep1.jpg Which would seem to imply that the answer is true. If you're wondering if it's out of context, here's all the text on the page: http://img.photobucket.com/albums/v1...allas/Jep2.jpg -- Dallas |
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