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1 February 2009

We haven't had something from non-mainstream physics for a while now (and I'm not talking about the many-worlds interpretation of quantum mechanics or something; just the stuff that's usually not clearly answered even in high school textbooks which should know better but obviously don't). So here's something from exactly 10 years back which had generated a humungous amount of flakback and faffing for a few following weeks.

How do siphons work? In particular, if you say they depend on atmospheric pressure, then how come some liquids can be siphoned in a vacuum? So do they depend on gravity? In that case when the siphon tube is first lowered into the liquid, why doesn't the siphon start itself? Also, what force actually pulls the liquid up the first arm against gravity? Finally, how is the height of a siphon limited -- especially when the siphon works in a vacuum? (Incidentally, don't even think of approaching a fluid dynamics "expert" because s(h)e might break out in cold hives in front of your aghast eyes.)

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Dear MS,

Just a bit of care is needed while handling the carry-overs; but otherwise this problem was a dud. Try to solve a problem yourself before running it; because if you can solve it, anybody else can! (Yeah but they don't pay me to solve the problems; just to pose them. -- MS)

Palomita Patel, palomita72@rediffmail.com

Too-Austen-Tatious-Dept:
(The main problem after the easy word problem was: ". . . What's the question that's not been asked?" -- MS)

I believe you will get myriad correct entries for the word problem question. And, funnily, I wouldn't have got the answer if you hadn't asked the question about the question not being asked. Somebody had rightly said that "Often the question is the answer itself!" So here's the answer: (J)AIL, (A)GREED, (N)EARLY, (E)MOTION, (A)STERN, (U)SURER, (S)IMPLY, (T)ROUBLES, (E)STRANGE, (N)EAT. The question is: "Who wrote Pride and Prejudice, Emma, Mansfield Park?" Or any other question whose answer is Jane Austen like "Who is my sister's favourite author?"

Mihir Pramanik, Kolkata, India

The longer words are: 1. JAIL; 2. AGREED; 3. NEARLY; 4.EMOTION; 5. ASTERN; 6. USURER; 7. SIMPLY; 8. TROUBLES; 9. ESTRANGE; 10. NEAT. Good thing, the last question (which is "Which famous literary figure is spelled-out by the first letters of the longer word answers in the order given" -- Jane Austen) -- it enabled me to correct my first answer to clue 4 from my first attempt: "Surge"!

Ben Cooper, Muscat, Oman

(1) SUFFER/PRISON; J-AIL; (2) ASSENTED/AVARICE; A-GREED; (3) IN GOOD TIME/ALMOST; N-EARLY; (4) MOVEMENT/FEELING; E-MOTION; (5) AFT/SEVERE; A-STERN; (6) MORE CERTAIN/MONEY-LENDER; U-SURER; (7) WITHOUT DIFFICULTY/SUGGEST; S-IMPLY; (8) DIFFICULTIES/FOREIGN CURRENCY; T-RIAL; (9) ODD/ALIENATE; E-STRANGE; (10) TIDY/DINE; N-EAT
The first letters together form JANE AUSTEN, an English writer whose novels include Pride and Prejudice and Sense and Sensibility

Pramod Janardhanan, pramodj@lycos.com

Double-Or-Quits-Dept:
(The Endgame was: "A number ends with the digit 2. If we move this 2 from the last place to the first, the new number is twice the original. What's the number" -- MS)

The answer is 105,263,157,894,736,842. Since the last digit '2' is going to be made the first digit of the doubled number, the original number must start with '1'. Moreover, as the last digit is '2', the last but one digit has to be '4' (since we are doubling the original number). Similarly, the last but two digit has to be '8' (double of last but one digit '4'). In this fashion, keep moving from right to left, and continue to derive the subsequent digits by doubling the previous digit, keeping into account the 'carry forwards' too, till you arrive at '1'. On reaching the digit '1' test the number for the required condition. You'll notice that it doesn't meet the requirements of the question on reaching the first '1'. Second time it does.

Sameer Bhargava, SameerB@mashreqbank.com

The number we are looking for is (hold your breath) 105,263,157,894,736,842. I derived it this way by writing an equation: 2x/2 = x2 (assuming the number to be two-digit). I found that whatever value x possessed, the last digit on the LHS would be 4. So I rearranged the equation as: 2x42 = x42. Here we see that whatever value x possesses, the second-last digit on LHS will be 8. So rearranging again, we get: 2x84/2 = x842 (note again that irrespective of value of x, the third-last digit on LHS is 6). Do I need to continue further and state that . . . (No you don't need to do any further damage -- MS)

Saifuddin Khomosi, Dubai,UAE

ENDGAME

The current world record in the Men's and Women's Discuss Throw stands at 74.08 and 76.80 metres respectively . All other records in athletics -- including shot put , javelin and hammer throw are better for males. So what's happening here? What's the explanation?
(Submitted by Dr Vivek Jain, Baroda, India)

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