Breaking News
Page 1 / 2   >   >>
User Rank
Rookie
re: Can you solve this brainteaser?
3/1/2008 12:15:09 AM
NO RATINGS
Hello everyone. No offense at first. It may not be such simple as we thought. What means a "brainteaser" ?

User Rank
Rookie
re: Can you solve this brainteaser?
2/29/2008 5:11:46 PM
NO RATINGS
When I first saw this, I was surprised that the answer is independent of the starting circumference. It's interesting that the answer is surprising, since I'm not surprised that circumference is proportional to radius. Maybe that means that the distributive property of multiplication is nonintuitive. I doubt the explanation is that simple, since another form of the question doesn't seem to be a riddle at all: A company pays each of its employees \$6.28 per hour, for a total of \$40,000 per hour. How much more would the company need to spend per hour to hire one more employee? C = 2*pi*R R' = R+1 C' = 2*pi*(R+1) = 2*pi*R + 2*pi = C + 2*pi Paul

User Rank
Rookie
re: Can you solve this brainteaser?
2/28/2008 7:01:19 PM
NO RATINGS
Try that again: The circumference is just over 40,000 km. I better give up :).

User Rank
Rookie
re: Can you solve this brainteaser?
2/28/2008 7:00:01 PM
NO RATINGS
on a completly different tangent: the string would stretch the extra approx. 2m as the requirement didn't specify tension to remain the same.

User Rank
Rookie
re: Can you solve this brainteaser?
2/28/2008 6:59:28 PM
NO RATINGS
Correction, I confused diameter with circumference. The diameter comes out to just over 40,000 km.

User Rank
Rookie
re: Can you solve this brainteaser?
2/28/2008 5:27:47 PM
NO RATINGS
I don't think any extra string is required. You already have 40,000 kilometers worth, which is way more than enough to encircle the earth.

User Rank
Rookie
re: Can you solve this brainteaser?
2/28/2008 5:06:25 PM
NO RATINGS
If string is lifted 1m, effective diameter increases by 2m. let d = 2meters. If D is original diameter then difference in circumference is C = (Pi*(D+d) - Pi*D) = Pi*d = 2*Pi meters = 6.283 meters

User Rank
Rookie
re: Can you solve this brainteaser?
2/28/2008 2:41:52 PM
NO RATINGS
If we assume a perfect circle of string then we can calculate the Diameter D C=Pi x D D=C/Pi = 40x10^6/Pi When you lift the string by 1 Meter, the diameter increases by 2 Meters. Then all you need to do is calculate the new circumference C and take the difference between old and new. NewC=(C/Pi + 2) x Pi To get the difference: Difference = NewC ? C = [(C/Pi + 2) x Pi ] ? C. = C + 2xPi ? C = 2xPi The answer I get is 2xPi Rick.

User Rank
Rookie
re: Can you solve this brainteaser?
2/28/2008 12:32:12 PM
NO RATINGS
It would be interresting how this equation looks, which gives the result how far we have to move to north or south... A real topic for my math teacher, who teased me with such questions back in school some decades ago.

User Rank
Rookie
re: Can you solve this brainteaser?
2/28/2008 11:07:10 AM
NO RATINGS
NO extra string needed to fill the gap if we could move our position towards southpole or northpole a little.

Page 1 / 2   >   >>

Flash Poll

#### Datasheets.com Parts Search

##### 185 million searchable parts (please enter a part number or hit search to begin)
Frankenstein's Fix, Teardowns, Sideshows, Design Contests, Reader Content & More

Editor’s Note: Excerpted from Lauren Ipsum: A story about computer science and other improbable things, author Carlos Bueno introduces us to Lauren and her adventures in ...

I remember when the first iPad came out deep in the mists of time we used to call 2010. Actually, that's only four years ago, but it seems like a lifetime away -- I mean; can you remember ...

latest comment David Ashton

Vincent Valentine is a man on a mission. He wants to make the first house to ever have a telephone into a telephone museum. Without help, it may not happen.

As every developer knows, there are the paper specifications for a product design, and then there are the real requirements. The paper specs are dry, bland, and rigidly numeric, making ...

latest comment MWagner_MA
Special Video Section
The LT8640 is a 42V, 5A synchronous step-down regulator ...
5:52
The LTC2000 high-speed DAC has low noise and excellent ...
5:14
How do you protect the load and ensure output continues to ...
6:54
General-purpose DACs have applications in instrumentation, ...
7:34
Linear Technology demonstrates its latest measurement ...
10:29
Demos from Maxim Integrated at Electronica 2014 show ...
4:17
Bosch CEO Stefan Finkbeiner shows off latest combo and ...
5:59
STMicroelectronics demoed this simple gesture control ...
2:15
Keysight shows you what signals lurk in real-time at 510MHz ...
4:17
TE Connectivity's clear-plastic, full-size model car shows ...
3:42
Why culture makes Linear Tech a winner.
6:08
Recently formed Architects of Modern Power consortium ...
6:39
Specially modified Corvette C7 Stingray responds to ex Indy ...
8:52
Avago’s ACPL-K30T is the first solid-state driver qualified ...
2:42
NXP launches its line of multi-gate, multifunction, ...
4:56
Doug Bailey, VP of marketing at Power Integrations, gives a ...
9:28
See how to ease software bring-up with DesignWare IP ...
5:19
DesignWare IP Prototyping Kits enable fast software ...
4:01
This video explores the LT3086, a new member of our LDO+ ...
7:03
In today’s modern electronic systems, the need for power ...
5:48