Physics: Post your doubts here!

[princeali97]

Can anyone explain why pressure at the top of a mountain is lower than pressure at sea level?..

 

[ZaqZainab]

Can anyone explain why pressure at the top of a mountain is lower than pressure at sea level?..

air has weight
as you move upwards there are less air particles ABOVE YOU being pulled by gravity
Also, on a mountain top, you are away from the center of earths gravity so the air weighs less at that height.

 

[princeali97]

air has weight
as you move upwards there are less air particles ABOVE YOU being pulled by gravity
Also, on a mountain top, you are away from the center of earths gravity so the air weighs less at that height.

Why cant we answer this question on the basis of temperature?Temperature at the top of a mountain is lower than temp. at sea level.So molecules will more kinetic energy at sea level and will apply greater force hence greater pressure.:/

 

[ZaqZainab]

Why cant we answer this question on the basis of temperature?Temperature at the top of a mountain is lower than temp. at sea level.So molecules will more kinetic energy at sea level and will apply greater force hence greater pressure.:/

Then the question arises why is it cold at higher altitude? It goes this way its cold because there is less pressure
the pressure is not less because of the temperature being low
the cause for temperature being low at high altitude is pressure
and the cause of low pressure is the weight of air.....

 

[princeali97]

Ahhh!.....im confused.As far as i know temperature does affect the pressure because as temperature increases the vibration and movement of molecules increases and so the frequency of collisions and the force they exert increases.

 

[ZaqZainab]

I don't think that temperature affects the pressure of air in anyways. And moreover kinetic energy also has no direct relation with pressure.

it does more the temperature more the pressure
what is pressure?continuous physical force exerted on or against an object by something in contact with it.
when you increase Kinetic energy more molecules start exerting force on the walls of a container hence higher pressure

 

[princeali97]

it does more the temperature more the pressure
what is pressure?continuous physical force exerted on or against an object by something in contact with it.
when you increase Kinetic energy more molecules start exerting force on the walls of a container hence higher pressure

Exactly!

 

[ZaqZainab]

Ahhh!.....im confused.As far as i know temperature does affect the pressure because as temperature increases the vibration and movement of molecules increases and so the frequency of collisions and the force they exert increases.

yes but why does the temperature change?
You aren't getting what i am saying
let me take an example i switched on the AC because it was hot
this doesn't mean It became hot when i switched on the AC
do you get it?
the reason there is low pressure is not because of low temperature
the reason there is low temperature is because of the low pressure
and so the reason there is low pressure is because of less air (weight) as i explained before

 

[princeali97]

yes but why does the temperature change?
You aren't getting what i am saying
let me take an example i switched on the AC because it was hot
this doesn't mean It became hot when i switched on the AC
do you get it?
the reason there is low pressure is not because of low temperature
the reason there is low temperature is because of the low pressure
and so the reason there is low pressure is because of less air (weight) as i explained before

Okay i get it.But how can low pressure cause a low temperature at the top of the mountain? that can also be a good question

 

[ZaqZainab]

Okay i get it.But how can low pressure cause a low temperature at the top of the mountain? that can also be a good question

yeah it can be

do yo want me answer this?

 

[kitkat <3 :P]

Exactly!is a mountan/quote]
Lets take example of two cities quetta and karachi quetta Is a valley and has mountains mountains have hieght and something which has height less air would be there above it so less pressure hence quetta is cold
if we take example of karachi its at sea level means not at hieght which means more air above the area that means pressure will automaticall increase because of more air henxe temp will increase

 

[princeali97]

yeah it can be

do yo want me answer this?

ofcourse!

 

[princeali97]

great! good example! I wish Karachi had some mountains

 

[ZaqZainab]

ofcourse!

lol i though you got it

it does more the temperature more the pressure
what is pressure?continuous physical force exerted on or against an object by something in contact with it.
when you increase Kinetic energy more molecules start exerting force on the walls of a container hence higher pressure

the same this but this case
when you decrease pressure the kinetic energy of a molecule becomes less and so less molecules exert that much force and so temperature decreases

 

[princeali97]

i got it i got it i got it!!!...phew! thanks zainab..thank u very much

 

[ZaqZainab]

i got it i got it i got it!!!...phew! thanks zainab..thank u very much

where did you get this question from or was it just a random one?

 

[princeali97]

where did you get this question from or was it just a random one?

it was a past paper question.I don't remember the year.It was in between year s05 and w13. keep searching

 

[ZaqZainab]

it was a past paper question.I don't remember the year.It was in between year s05 and w13. keep searching

lol maybe i will come across it some time

 

[princeali97]

lol maybe i will come across it some time

Pls do share questions that u find confusing.It will really help us.

 

[ZaqZainab]

Pls do share questions that u find confusing.It will really help us.

I will