Mt. Everest vs Mt. Godwin Austin
Suppose you and a friend set out on separate climbing expeditions, you to Mt. Everest and your friend to Mt. Godwin Austen. You both bring identical cooking equipment and intend to cook rice for dinner with equal volumes of water.
On which peak is the rice going to cook faster?
The peak of Mt. Everest (left) is
8
8
4
8
m
above sea level. The peak of Mt. Godwin Austen (also known as K2, right) is
8
6
1
1
m
above sea level.
- Mt. Everest image credit: Joe Hastings . CC BY 2.0
- Mt. Godwin Austen (K2) image credit: Svy123 . CC BY 3.0
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16 solutions
Moderator note:
There has been a lot of great discussion for this problem, some involving comparison to cooking times at sea level, and some considering pressure cookers as an alternative way of cooking the rice. All these tangents have made it a bit difficult to find the core physical mechanism to the cooking rate on these two mountains.
As Ram has stated above, the boiling point of water decreases with an increase in altitude, so water will boil at a higher temperature on Mount Godwin-Austen than on Everest . But cooking rice doesn't really have anything to do with boiling water. Like most cooking, the texture change that occurs in rice is temperature dependent: the rice will cook faster at a higher temperature.
The important point that some are missing is that liquid water can not be heated above its boiling point at ambient pressure , any extra heat that is put into the liquid water contributes to the heat of evaporation, not increasing the temperature of the water. So at the lower altitude of Mount Godwin-Austen, the water can be heated to a higher temperature during cooking, which will cook the rice faster.
That is also the reason it is easier to boil stuff in the Himalayas
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I DIDN'T GET YOUR POINT ?
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If you put things in a pressure cooker … sorry
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@Mohammad Farhat – Yes you are correct now. In pressure cookers pressure is more and hence food gets cooked fast. But do you know pressure is not the only reason for fast cooking of food in pressure cookers, there is also another reason which I am going to post in my next question.
Pressure can vary with the weather. The difference between a relatively strong high-pressure system and a relatively strong low is about 5% pressure difference. The mean pressure difference associated with the altitudes of these mountains is only about 3%. They are over 130 km apart so the weather can easily be very different.
I don't disagree with your answer but on a very nice day on Everest you might have a higher boiling point than during a storm on K2.
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You won't climb a mountain in storm, so I guess we can assume the weather in both cases is good, i.e. similar.
Sorry I didn't understand the last part of the explanation. If the water boils at a higher temperature at Mt. GA, how does it make rice cook faster? Isn't a higher boiling point indicative of longer time to heat the water up and hence the rice taking longer time to cook? Can you pls explain.
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We are only comparing between the case in Mt. Everest and in Mt. K2. The thing here to understand is when compared to Everest rice cooks faster in Mt. Godwin Austin. But it may not be as fast as on sea level.
The time it takes for the water to reach a boil is irrelevant, since the water will heat up at the same rate at both locations. The difference is the maximum temperature the water will reach, as the hotter water will cook the rice faster. A higher boiling point means hotter water which means rice will cook faster.
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At Everest, the water boils at a temperature less than 1 0 0 ∘ C . On Godwin Austin too the water boils at temperature less than 1 0 0 ∘ but it is more than that n Everest. So, when compared to Everest water boils at a higher temperature in Godwin Austin and hence rice cooks faster there when compared to Everest . I am stressing the word compered to because in this question you are just comparing 2 peaks and not peaks with sea level.
I know this is a math question, but rice is not cooked with boiling water. You heat up the water on the lowest gas on your equipment. Therefore, the change in the boiling point of water would not affect the cooking time of rice; because the cooking time would be dependent entirely on the heat dispersion and absorption of the equipment, which are stated as the same for both parties in the question.
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Well, it depends on the boiling point at that altitude, doesn't it? It may be true that at sea level, you don't need to hit boiling point to heat the rice enough, but if the boiling point is low enough then you might have to boil the water.
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Yes. This is my point and you have understood it.
That is true, if I understand you correctly. Suppose we cook rice in water at 50 degrees Celcius. So if we are on such a high altitude that the boiling point of water is 40 degrees, than yes, it will take longer to cook. This edge case shows that the cooking time of rice on a higher altitude is not necessarily slower than sea levels. Thus, the question should have been asked as "which peak is the rice might be cooked faster?".
Elaborating even more on the question; the boiling point of water is well above the minimum rice-cooking degree for both Mt. Everest and Mt. Austin. Therefore, I would still argue that cooking times are equal. I mean if this was a trick question, than I would expect all the details to thought-out.
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@Hazar İlhan – Your edge case is legitimate, but I think rarely do we cook rice at a fixed temperature like 50 degrees Celsius. Normally you apply heat to your rice and water, the heat makes the water swell and soften the rice faster, and often some of the water is converted to steam at the end of cooking to "steam" the rice and provide a nice consistency.
Do you agree that the rice will cool faster if it reaches a higher temperature during cooking? If an individual on K2 and an individual on Everest both want to cook rice quickly to fill their empty stomachs, which individual will be able to cook it faster? Since the liquid water's temperature can never surpass the boiling point at that location, the peak temperature at K2 will be higher, and so the rice can be cooked faster.
This is a bogus question. Rice takes the same amount of time to cook regardless, because it's a matter of cooking temperature, not water evaporation.
Water boils more quickly at higher altitude, but at a lower temperature. It's quite likely that the rice will take longer to cook. I know from experience that dried beans take significantly longer to cook in camp on Mt. Rainier than in Minneapolis, MN.
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You're absolutely correct when you say that rice (and bean) cooking time is a matter of cooking temperature, not water evapouration.
But answering this question also has nothing to do with water evapouration. The key point here is that liquid water can never get any hotter than its boiling point at the ambient pressure . So at a lower altitude, you can heat water to a higher temperature, which will cook food faster.
The thing you should note here is that the rate of cooking is not dependent on the rate which rice absorbs water. when water is boiled in a pressure cooker it produces steam and as steam cannot escape from the cooker it increases the pressure and as a result the temperature increases and food gets cooked faster. On Everest and Godwin Austin water boils at temperature lower than 1 0 0 ∘ so enough steam won't be produced and as a result temperature decreases and cooking becomes slow. But, when compared to Everest water boils off at a higher temperature on Godwin Austin and hence more steam is produced, temperature increases and cooking gets faster.
Regarding the statement which you made to my question, a problem in the problems of the week cannot be a bogas one. Do you know how difficult it is to write a problem for problem of the week. Out of thousands of problems which come in community from the users every week only 15 out of them are selected as problems of the week (5 each in Basic, Intermediate, Advanced). So, you can tell about the quality of the problems of the week. Every question in problems of the week (especially science questions) is a crystal.
I think this is a bogus question too. The water will boil away faster on Everest because the boiling point is lower at a higher altitude. The problem stated an equal amount of WATER. Therefore cooking is completed when the water boils away or is absorbed by the rice.
Very likely, the rate at which rice absorbs water is dependent upon a higher temperature, but that fact is not in the problem statement.
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You say that water will boil of at a lower temperature on Everest and it is correct. So, go a little further. If water boils of a temperature less than 1 0 0 ∘ the heat released will be less when compared to sea level . So, the cooking will be slower when compared to sea level . Many of them are getting wrong here itself. The question asks only to compare between Everest and Godwin Austin but it doesn't ask to compare peaks and sea level . As, Godwin Austin is at a lower altitude than Everest water boils off at a higher temperature than when it is on Everest. So, the heat supplied will be more when compared to that of Everest . Hence, cooking will be faster in Godwin Austin when compared to Everest .
The thing you should note here is that the rate of cooking is not dependent on the rate which rice absorbs water. when water is boiled in a pressure cooker it produces steam and as steam cannot escape from the cooker it increases the pressure and as a result the temperature increases and food gets cooked faster. On Everest and Godwin Austin water boils at temperature lower than 1 0 0 ∘ so enough steam won't be produced and as a result temperature decreases and cooking becomes slow. But, when compared to Everest water boils off at a higher temperature on Godwin Austin and hence more steam is produced, temperature increases and cooking gets faster.
Regarding the statement which you made to my question, a problem in the problems of the week cannot be a bogas one. Do you know how difficult it is to write a problem for problem of the week. Out of thousands of problems which come in community from the users every week only 15 out of them are selected as problems of the week (5 each in Basic, Intermediate, Advanced). So, you can tell about the quality of the problems of the week. Every question in problems of the week (especially science questions) is a crystal.
You are assuming that they both climbed at the same speed. Maybe one did not make it to the top.
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The question mentions that they did this only when they reached the peak.
I have made changes to my solution. I hope that now it is much better and clear.
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How to send questions for problem of week?? And also, how to make question sets??
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We cannot write problems of the week. Only staff will select questions from community and will select them as problems of the week. For creating sets click the option sets which with be below the solutions option and then click on create set. You can either directly wrie problems in it by clicking "Add new Problem" or you can save any question into the set.
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@Ram Mohith – Where is Solutions option ?? Sorry for disturbing
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@Mr. India – In your profile.
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@Ram Mohith – I have created the set but how to add questions??
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@Mr. India – Go and check in the set. At the bottommost point there will be two options "Add new Problem" and "Add new Note" . Click on add problem and you can write the problem and post it. It will be automatically be saved into the sets
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@Ram Mohith – Can this be done on phone?In my phone this option isn't there
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@Mr. India – It will be available in mobile too. But you must click the option "view full site" to do it.
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@Ram Mohith – And where is this option,I can't find this too :-(
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@Mr. India – Manuj Rajpal, please come to this note as you can get more help. This place is meant for only solution discussion.
The height of the mountain isn't relevant as much as the distance between the peak and the atmosphere. It would matter the same if the earth was perfectly round, but it isn't. Earth is more of an oval-shaped plant, Hence mountain Chimborazo is closer to the atmosphere then Mt. Everest despite being only 6,268 m' in height.
The only variable are the rate at which the rice absorbs heat and the capacity of the heat source. If you were grilling on a George foreman for instance it wouldn’t make a damn bit of difference so the question should be can you increase the temperature of a fluid past it’s boiling point at ambient pressure
This is a terrible question for a lot of reasons. In addition to those others have said, the two mountains are so close in height that local atmospheric conditions will cause a difference in air pressure greater than that caused by their altitude. You could have sent one to Death Valley and one to Mt Everest, just to make it clear that the altitude is the most significant factor. And have them boiling an egg to hard-boiled, where it is the temperature of the water boiling that is so significant. How about this: "Suppose you and a friend set out on separate adventures -- you climb to the top of Mt. Everest and your friend hikes to the lowest point of Death Valley. Each of you brings an egg with you, planning to cook it to hard-boiled. Once the water is boiling, you lower your egg into the water and cook until it is hard boiled. Which of you should cook the egg for longer? (Assume that the internal temperatures of the eggs was the same before being put into the boiling water.)"
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I agree. I knew the rice at mount Austin would cook faster sure but since they're both at such high altitudes. The rate of speed to cook the rice is so small between the two it shouldn't be a factor
One could argue that on the Everest, water will start boiling sooner than on Godwin-Austen therefore the rice will start cooking sooner and might very well finish cooking sooner as well :-)
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It's not the boiling that cooks the rice. It's the water temperature.
This question should be changed to "if heating conditions (rate, ambient temperature, equipment) are identical on both mountains, at which location will water boil sooner."
I arrived at the correct answer using an entirely different approach, maybe pure luck. I took the statement that they both used the same equipment as a clue. We know oxygen levels decrease with altitude, so the stove on K2 has more available O2. This results in better combustion, higher heat and faster cooking. Any validity to this approach?
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Very interesting approach! You're right I think, that any stove relying on combustion will heat less efficiently at higher altitudes, and cook the rice slower. Definitely a valid answer to this problem, though from a very different point of view.
It's an empirical fact that cooking time increases at high altitudes, like most things, this effect is probably a combination of boiling point temperature, decreased efficiency of fuel burning, and maybe other factors we haven't thought of.
I disagree with the logic approach. Cooking time includes the time to boil and the time for the rice to absorb the water. Granted the absorption times are not effected by the altitude. However, the boiling time is, and therefore, reduces the overall cooking time. If the question put in a clause that stated from the time of boil the time measurement begins, then I would agree.
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Why would cooking time include time to boil? Boiling itself does not cook the rice any faster, the cooking time depends on the temperature of the water (which can become greater on the lower altitude peak).
If we use pressure cooker then in both places it will take same time . Am I right??
Why does everyone assume that it is necessary for the water to boil? I've cooked a lot of rice, and it depends on the temperature, not whether or not the water is boiling. I agree with you!
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I’m with you too. It’s the heat that cooks the rice, not the water evaporating.
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As pointed out by another commenter, water stops increasing in temperature once it starts boiling. So on Everest, the water boils at a lower temperature, meaning the maximum temperature achieved is lower.
Temperature won't increase as the water changes phase during boiling, so it is impossible to get the rice to as high of a temperature to even do the cooking. So it isn't that the water has to boil, but that there is a lower limit on how hot the water can even be gotten as the altitude gets higher.
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You can cook rice in room-temperature water, you just let it sit long enough to absorb water and soften.
Heating rice simply speeds this process up and allows the water to petrate the rice faster, giving a consistent texture.
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@Kevin Higby – "You can cook rice in room-temperature water, you just let it sit long enough to absorb water and soften." That's not cooking.
David nails it. The problem with cooking at altitude is that it's very hard to get the water hot enough to cook. It boils away at a lower temperature.
It depends. Does the pressure cooker bring the contents to a set pressure, or does it increase the pressure by some amount or percentage compared to the ambient temperature?
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My pressure cooker has a small opening on top with a heavy weight fitted on top of it. When the pressure inside the vessel gets above the working pressure of the cooker (5 bar? something like that?) then it is enough to slightly lift the weight, and for some pressure to escape. In this way the pressure cooker remains around its working pressure.
Seems that Akela's lateral thinking is right to me, though I don't want to be the one that has to drag a pressure cooker up K2 or Everest.
I think this is not entirely true.. if you put the rice in the pressure cooker at the same pressure you are right but if you put the rice inside the pressure cooker at both tops of the mountains then you will start with a lower pressure and have to compensate that before you get to the same point of the lowest mountain so it will take a bit longer at the mount Everest
Ideal Gas equation ( PV=nRT ) says, if P decreases T decreases so even if we put rice inside both pressure cookers and bring those from the same lower part at different heights, we can easily understand that, because of being metal pressure cookers, the one at higher altitude would be a bit colder than the one at a lower altitude. So, the first one at high altitude would take more external heat to raise the temperature of water at any level as compared to the one at low altitude. Am I correct? Please do comment if I am mistaken. Thank you.
Your assumption is not fully correct. Although you cook rice in pressure cooker, the temperature at which water will boil off will be different at both the peaks.
no the rice cooks faster on the lower peak because of lower altitude.
What if we pressurize the pressure cooker to normal sea level atmospheric pressure? Then does it take the same time on both peaks?
This is because boiling point of a liquid is directly proportional to atmospheric pressure which lowers as height increases. Hence the atmospheric pressure is higher on Mt.K2 and water boils at a higher temperature cooking rice faster.
I understand that water will come to its boiling point sooner at higher altitude. But how does that make rice cook faster? The rice will need to spend the same time in hot water regardless of how quickly that water came to boil, isn’t that right?
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My thoughts exactly. The boiling of the water is useful only to serve as a visual indicator of its temperature. A thermometer accomplishes the same thing with greater precision.
Check my solution. I have edited. Still if you have any doubts you can ask.
Wouldn't having the water boil at a lower temperature increase the speed at which it cooks?
Has anyone done the actual real life calculations showing Very slight temperature change in provement and with the higher temperature temperature increase at K2 compared to Everest Are you telling me that a 1° temperature difference is really that significance in cooking ? PV equals nRT. Both locations are extremely difficult for cooking and I find it silly that 600 feet of air pressure is going to make a hill of beans difference in cooking time
Does rice cooks faster on the first floor of a high-rise apartment building compared to his 60th floor in the same apartment building Theoretically yes a practical way I would say no
When water boils it produces steam, right? Reguardless of temperature right? I’m basing my question on asuming that it does. My question is why does the fact that water boiling at temps less than 100 on either mountain, automatically mean enough steam will not be produced.
It may not even be possible to cook the rice at these altitudes without the use of a pressure cooker. As water boils at a much lower temperature due to the low atmospheric conditions, the water will never get warm enough to properly cook the rice.
Yes you are correct. But it is possible to cook food there but it takes more time. And the question asks at which peak will the cooker goes faster.
Density of the air is higher closer to the sea level. Therefore, there is more oxigen, as a result better burn.
The temperature is warmer on mt.Godwin Austen Becuase the mt. is closer to the ground,and in colder climates it is harder to cook food so the answer is mt.Godwin Austen.
As you go higher, the air pressure gets lower, which lets your water start to boil at a lower temperature. Once it starts boiling, any more heat added is lost as the water boils away (evaporates), so the water cannot get any hotter. Therefore, as you go higher, your water boils at a lower temperature, and your rice takes longer to cook.
Boiling point of water is reduced because of a decrease in air pressure at higher altitude which makes water molecules escape the surface faster. So at a higher altitude cooking time is longer because the boiling point of water is lower
69 degr on Mt. Everest , so on 8848m Boiling water is 69 degr. and on Mt. Godwin Austin is on 8611m and Boiling water is ? >>> 8611*69/8848=67 degr ... so its peak Godwin Austin is were the rice will going to cook faster.
In order for the rice to cook, a certain pressure and temperature have to be reached before water in the pan starts boiling. Therefore at a lower altitude, this temperature and pressure will be reached faster as compared to a higher altitude
Technically, alpinists use very lightweight equipment, so the pressure cooker is not a viable alternative here.
The altitude / pressure factor in boiling point is accurate : generate speaking, it take between two to three times the amount of time to cook pasta at 3000 feet, plus about a minute every 1000 feet. 189m of difference, 620 feet, should add 30 seconds of cooking time, but the water starts to boil faster, so you pour the rice in sooner. I don't know how that factors out.
Outside temperature and winds are also important factors in cooking equipment efficiency.
Your friend will reach the peak of Mt. Austin first. As a result your friend will cook the rice first before you reach the peak of Mt. Everest.😂
Wouldn't the rice cook faster on Mt. Godwin Austin because it is colder on Everest?
Not true. A pressure cooker depends on pressure, not temperature.
it depends from the recipe.
This one (risotto alla milanese) takes the same.
Melt 25g of butter with the olive oil in a large saucepan, add the onion and cook until is soft but not coloured. Meanwhile warm up the beef stock and add the saffron. Add the rice to the onion, saute the rice in the pan over medium heat for 5 minutes until lightly toasted. Add 3/4 cup dry white wine and the stock a ladleful at a time, stirring continually and adding more once the previous lot has been absorbed. It will take 20 minutes. The risotto should be yellow, soft and creamy but there should be a very slight bite in the centre of each grain. Add parmesan stir in and leave for some minutes before serving.
Does this solution applicable at night time also?
The surrounding / room tempetature at a lower altitude is less. Thus at the same conditions the one at a relatively higher altitude will get a lesser maximum temperature than the other.
Obviously this means that the rice cooker in the lower altitude will get cooked faster.
You are assuming that the water you are cooking the rice in is at boiling point. Personally when I'm cooking rice I bring the water to the boil then reduce the heat so it's just off the boil before adding the rice. It doesn't matter whether the boiling point of the salt water is 98 degrees or 104 degrees if you keep the temperature at 95 degrees. The amount of salt added to the water will have a greater affect than the small difference in elevation.
Here is my explanation for simplicity's sake. Considering the factors stated in the problem, we should take note that as we increase in altitude, there would be less oxygen available for a fire to be started. Hence, the efficiency of cooking at Mt. Godwin Austen (8 611 m above sea level) is better than at Mt. Everest's (8 848 m above sea level).
P S : Remember that a fire needs oxygen, heat, and fuel in order to start the combustion. This is normally what we call the fire triangle.
So, it is clear the boiling point of water decreases with increase in Altitude. So, higher one goes into atmosphere less is the boiling point of water. As, Mt. Everest is higher than Mt. Godwin Austin water boils at a higher temperature at Mount Godwin Austin when compared to that of Everest . Therefore, rice cooks faster there.
The thing you should note here is that the rate of cooking is not dependent on the rate which rice absorbs water. when water is boiled in a pressure cooker it produces steam and as steam cannot escape from the cooker it increases the pressure and as a result the temperature increases and food gets cooked faster. On Everest and Godwin Austin water boils at temperature lower than 1 0 0 ∘ so enough steam won't be produced and as a result temperature decreases and cooking becomes slow. But, when compared to Everest water boils off at a higher temperature on Godwin Austin and hence more steam is produced, temperature increases and cooking gets faster.
Note : This is the reason why it is difficult to cook food in Himalayas.
Regarding the comments being posted, you should compare only Mt. Everest and Mt. Godwin Austin but not to compare the peaks with sea level.