Phixx Quizz 6 : Saving gas

[knotman]

Back again. OK DW here we go again !
Q: You are bringing a pot of cold water to the boil, after a hard day in the paddle, to cook some potatoes. To do it using the least amount of energy you should
A: turn the heat on full force
B: put the heat on very low
C: put the heat on at some medium value.

Sennen

[Maurice]

I say \"B\".
Under higher pressure, much of the flame and its heat will be driven to the sides of the pot and then up, up and away! Smaller flame has heat source directly under the pot. Maurice. :ermm:

[DaveWalsh]

C.
Too high and much heat is lost up the sides, but too low and it gets blown away before it even reaches the bottom of the pot.
DW
PS That\'s assuming the energy you mean is the burning fuel, and not the paddler\'s depleted levels, it being cold and miserable etc.

[SeanHennessy]

As you heat the pot it\'s constantly losing heat to its surroundings through radiative cooling. So it\'s more efficient in general to use as high a flame as possible. So long as \"full force\" doesn\'t cause excessive flame spillage, then I reckon A is your man.

[Mary]

Ans=D... add salt to the water.. impurities raise boiling point so spuds will cook faster!
MTBPost edited by: mary, at: 2007/09/19 01:44

[ciaranclissmann]

Mary\'s making this up.

[Mary]

It\'s true .....
\"Adding salt, for example, raises the boiling point of water. This is why
many recipes call for the addition of a small amount of salt to boiling
water -- it causes the water to \"cook\" what you are placing in the water at
a higher temperature. The boiling point of a solution is a colligative
property (you may read more about these at
http://www.infoplease.com/ce6/sci/A0812887.html). The addition of salt not only raises the boiling point of water, it also lowers its freezing point
(which is why people will put salt on their steps and walkways in the
winter).
Also, directions for cooking rice and other items that require boiling water will specify that longer cooking times are required at higher altitudes (such as for people living in Denver, CO). This is because the lower atmospheric pressure at high altitudes means that water will boil at a lower temperature there.

Regards,

Todd Clark, Office of Science
U.S. Department of Energy\"

So now.
MTB

[Maurice]

Knotman!!!!! You have a lot to answer for (and far too much time on yer hands)........................ Still think \"B\"! Mo.

[knotman]

Wow ,this is great.
Answers A,B and C.
This one could heat up all right.
Mary is not making things up. Mary is indeed correct. Raoult is the name of the guy who, as most big headed and self-important scientists of old, gave his name, not unsurprisingly, to Raoult\'s Law in chemistry.
On the subject of boiling potatoes, clean sea water adds a lovely flavour to our spud. An old Indian trick!

Answer withheld for another while. Cheers Sennen.

[Dermot]

As the question is phrased, surely the amount of energy \'used\' to boil the [same amount] of water is the same no matter which method is adopted? Energy cannot be either created or destroyed....and all that. If you are considering the amount of energy \'lost\' or potentially lost then there are so many possible varibles that interrelate and may make a difference to the best method/setting - such as size and shape of pot; location (Sahara noon or Greenland); type of stove (isn\'t this the principle of the new MSR and other super-stoves?); use of lid; material; purity of water (as noted); etc.

I say....pretend they are apples, and eat \'em raw!.... or emigrate, like so many did the last time there was a serious potato problem here!

Dermot