# Riddles with a Prize, by Mantus Anchors



## Mantus Anchors (Dec 13, 2011)

Ok here are the rules: I will post the riddle and the first person to answer the riddle correctly gets to win a Stainless Steel Mantus Hook with free shipping.
We will try it this week and see how it goes,,, 

Ok so here is the riddle:

There are three switches downstairs. Each corresponds to one of the three light bulbs in the attic. You can turn the switches on and off and leave them in any position. 
How would you identify which switch corresponds to which light bulb, if you are only allowed one trip upstairs?

Post the answer on this thread first and win a Mantus Chain Hook!


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## AlaskaMC (Aug 19, 2010)

Dang! I know the answer to this and yet I don't have a sailboat that would merit a hook as kingly as yours yet. So I will let it go to the next bidder. 

Stupid dingy sailing!  Guess I need to step up the search. I am already an anchor short!


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## tdw (Oct 2, 2006)

Sent you a PM with the answer but I'm guessing that being in Australia I'm not eligible for the prize. 

Shame, I'm in the market for a hook.

Andrew B

Actually on second thoughts I don't think moderators should be eligible.

ab


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## svzephyr44 (Jun 26, 2000)

Flip one switch on and wait a minute. Flip it off and flip another switch on. Go to the attic. The switch you just flipped corresponds to the light that's on. Feel the two bulbs that are off. The switch you flipped first corresponds to the hot bulb, while the switch you never flipped corresponds to the room-temperature


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## SchockT (May 21, 2012)

svzephyr44 said:


> Flip one switch on and wait a minute. Flip it off and flip another switch on. Go to the attic. The switch you just flipped corresponds to the light that's on. Feel the two bulbs that are off. The switch you flipped first corresponds to the hot bulb, while the switch you never flipped corresponds to the room-temperature


So, is this the winner?


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## pdqaltair (Nov 14, 2008)

I'd have bought one by now if it came in 1/4-inch, but it does not from what I can see. How about it?


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## Sea Diamond (Jan 2, 2012)

I believe this has been answered correctly, but since I am on the hunt for a new anchor for my girl Sea Diamond, (Beneteau Oceanis 38), I'll put my name out there for advice on your recommended model. So far, I've had good resuts with a 35lb CQR, but it is now a bit "kinky" after a collision with a huge nav aid that was hiding out behind the jib. Oh well, if only once every 30 years I guess that's OK - best thing though, the crumpling of the anchor totally protected the boat from any damage whatsoever. (Just dumb luck on that one). Oh yeah, the nav aid was one of those HUGE barrels the navy uses for mooring (they call then "Trot Buoys")About 15ft. diameter and 30 ft. long floating on its side and cladded with 4x4 timbers - it too was un harmed.

For the record, I agree with a previous post...
Activate Sw#1 for 5 minutes. Turn it off. 
Activate Sw#2 and immediately RUN to the actic. 
Lit bulb is Sw#2, Hot bulb is Sw#1 and cold bulb is Sw#.

Hopefully the original poster has already won an anchor, but maybe I will get an opinion on an anchor type for my 38 ft. 17,000 lb. Beneteau. Anchorage is usually mud bottom - I have a Danforth for backup/sandy bottom.

Les


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## eherlihy (Jan 2, 2007)

svzephyr44 said:


> Flip one switch on and wait a minute. Flip it off and flip another switch on. Go to the attic. The switch you just flipped corresponds to the light that's on. Feel the two bulbs that are off. The switch you flipped first corresponds to the hot bulb, while the switch you never flipped corresponds to the room-temperature


What if the bulbs in the attic are fluorescent? About two-thirds to three-quarters less heat is given off by fluorescent lamps compared to an equivalent installation of incandescent lamps. This greatly reduces the size, cost, and energy consumption.


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## Mantus Anchors (Dec 13, 2011)

TDW won this one!!! Congadulations on the new Mantus Hook
and in just a few minutes....
Stay tuned we will play again but I have to warn you questions will get harder until the finale.....


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## sailor25b (Jun 2, 2006)

The lightbulb just went on in my head, as I realized that this is "enhanced" advertising on a sailing forum (from a sponsor, so I guess it's ok). Nothing to do with sailing or anchors, but what the heck. Clever, clever!


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## Mantus Anchors (Dec 13, 2011)

pdqaltair said:


> I'd have bought one by now if it came in 1/4-inch, but it does not from what I can see. How about it?


Given have that 5/16 is only 1/6 bigger than 1/4, the 5/16 Hook will have a little more slop in it but still will serve you right.... Try it if it doesn't work we will refund you.....
Greg


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## CalebD (Jan 11, 2008)

tdw said:


> Sent you a PM with the answer but I'm guessing that being in Australia I'm not eligible for the prize.
> 
> Shame, I'm in the market for a hook.
> 
> ...


Naaah. Aussie's and Maderator's are people too. Congrats TDW!
Perhaps Mantus needs a few contacts down under to set up distribution there.

Now if the rest of us who are still sitting in the dark could have a peek at the accepted correct answer ...


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## Mantus Anchors (Dec 13, 2011)

There were many right responses, but TDW was the first!!! 

tdw 
Super Fuzzy Moderator
Country: 
Join Date: Oct 2006
Location: Sydney Australia
Posts: 10,588
Rep Power: 10

Riddle Answer
Turn two of the light switches on. After a couple of minutes turn one of them off, then enter the room. One light will be on, two will be off but one of the two will be warm to the touch.

Cheers

Andrew B


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## tdw (Oct 2, 2006)

CalebD said:


> Naaah. Aussie's and Maderator's are people too. Congrats TDW!
> Perhaps Mantus needs a few contacts down under to set up distribution there.
> 
> Now if the rest of us who are still sitting in the dark could have a peek at the accepted correct answer ...


Nah ... it feels too much like "cash for comment". Seems to me that Zephyr was the second to get it right so I'm passing to him. (her ? them ?)

I do stress however that if first prize had been a Hallberg Rassey 46 then I'd have trampled all over my moral scruples.


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## miatapaul (Dec 15, 2006)

tdw said:


> Nah ... it feels too much like "cash for comment". Seems to me that Zephyr was the second to get it right so I'm passing to him. (her ? them ?)
> 
> I do stress however that if first prize had been a Hallberg Rassey 46 then I'd have trampled all over my moral scruples.


That is funny. Good to see that some folks have scruples, even down under!


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## tdw (Oct 2, 2006)

miatapaul said:


> That is funny. Good to see that some folks have scruples, even down under!


Not sure about Down Under .... I am but an ordinary bloke .... like most blokes my scruples stop at my waistline.


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## Mantus Anchors (Dec 13, 2011)

Sea Diamond said:


> I believe this has been answered correctly, but since I am on the hunt for a new anchor for my girl Sea Diamond, (Beneteau Oceanis 38), I'll put my name out there for advice on your recommended model.
> Les




Les, as you can imagine there are many opinions on anchors choice and on this forum there are pages of discussion on the topic. My personal opinion is that newer generation anchors: Spade, Manson Supreme, Rocna, Mantus, Ultra offer a more reliable set than the competition. In really soft mud I think a Fortress or a big Dan forth actually are more efficient. What we claim is the most reliable set, especially in hard to penetrate bottoms. We concentrated on this feature bc in an emergency you don't have time to nurse an anchor or try to find a place where it will grab, another feature of the Mantus is that it breaks down for easy storage. I am sure other members of the Sailnet community would love to share their advice..... feel free to call me and/or private message me with questions any time..... 
PS sorry about the accident, glad the boat is OK
Greg


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## chucklesR (Sep 17, 2007)

Next riddle?????


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## Jeff_H (Feb 26, 2000)

Mantus Anchors said:


> TDW won this one!!! Congadulations on the new Mantus Hook
> and in just a few minutes....
> Stay tuned we will play again but I have to warn you questions will get harder until the finale.....


Of course Andrew (TDW) won. It is absolutely no fair since that questio n purtains what he does for a living. Andrew is a world renown and highly esteemed expert in lighting. Seriously, Goodonya Andrew.

Greg: Are you in Annapolis for the shows?

Jeff


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## Mantus Anchors (Dec 13, 2011)

chucklesR said:


> Next riddle?????


We are planning to post a riddle once a week on Monday mornings!
PS the prize on the last riddle was a Mantus Chain Hook not the anchor...
We will change the prize every week to keep things interesting....
I think this could be really fun....
Greg


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## Mantus Anchors (Dec 13, 2011)

Jeff we decided to go to Annapolis too late and could not get a spot, but we will surely be there in the spring! We still have not committed to the show schedule but will post it on the website as soon as we figure it out.....
Greg


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## chucklesR (Sep 17, 2007)

Greg, 
do you have any distributors in the Annapolis area? I seldom buy something as important as an anchor without putting a hand on it first.

Not that my fingers are good for tensile strength testing or such, it's just a thing..


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## Mantus Anchors (Dec 13, 2011)

No unfortunately we don't, but I can guarantee you that if you make a purchase through the Sailnet store and for any reason you don't like what you get or it just does not work for you I will refund you and pay for return shipping (no questions asked)...
Greg


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## Mantus Anchors (Dec 13, 2011)

Ok Guys the new Riddle:

Puzzle:

Velocity of Object 1 is constantly changing, but is always less than velocity of the Object 2. Object 2 velocity also changes constantly, but is always directed at the same angle as velocity of Object 1. Both objects are completely motionless relative to each other.
Be the first to describe a scenario when this happens and win a Mantus Hook.


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## eherlihy (Jan 2, 2007)

Two objects on parallel courses. With constantly changing velocity..

An example would be two sattelites whose orbits are 180º apart orbiting the same planet.


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## eherlihy (Jan 2, 2007)

... as viewed from a different planet.


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## Jeff_H (Feb 26, 2000)

You might check but I think that I saw some Mantus anchors at Fawcetts.


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## Mantus Anchors (Dec 13, 2011)

eherlihy said:


> Two objects on parallel courses. With constantly changing velocity..
> 
> An example would be two sattelites whose orbits are 180º apart orbiting the same planet.


Almost, but not yet!


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## jameswilson29 (Aug 15, 2009)

Actually, it would be like 2 satellites, one closer to the object being orbited. Since the distance is less, to remain motionless with respect to object 2, object 1 travels more slowly.


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## SeaQuinn (Jul 31, 2012)

What about the apparent wind and the wind?


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## DrB (Mar 29, 2007)

The key to this is the viewers angle to the two objects.

Object 1 and Object 2 are traveling on parallel courses. Viewer is either watching them go away or towards them so that the appear as point objects. Think of standing in the middle of a road and watch two cars slowly drive away from you. The distance that they are from each other never changes relative to your view point.

DrB


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## Mantus Anchors (Dec 13, 2011)

jameswilson29 said:


> Actually, it would be like 2 satellites, one closer to the object being orbited. Since the distance is less, to remain motionless with respect to object 2, object 1 travels more slowly.


Congratulations! Sorry it took me so long to respond.....
PM me your info and the chain size....
Next week we are doing a 8 lbs dinghy anchor...... Stay tuned...
Greg


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## blt2ski (May 5, 2005)

Mantus Anchors said:


> Congratulations! Sorry it took me so long to respond.....
> PM me your info and the chain size....
> Next week we are doing a 8 lbs dinghy anchor...... Stay tuned...
> Greg


I know I know........

"Who is she drives me boat, I drives me dinghy!!!!!!!!"

I've bet it all Alex! :laugher:laugher:laugher:laugher


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## jameswilson29 (Aug 15, 2009)

Thanks!


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## Mantus Anchors (Dec 13, 2011)

Ok Sailnetters! This one is for a 8 lbs Mantus Anchor as a prize.... Dinghy anchor...
By the way sorry I am late,,, but we had a problem with the surface finish of our hooks and have been busy refinishing the hooks and taking care of customers...... 

A sculptor named White, a violinist named Black, and an artist named Red meet in a cafe. One of the three says: " I have black hair, and you two have red hair and white hair, respectively, but none of us has a hair color that matches his name." White responds: "you are correct" What color is the artist's hair?


Greg


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## Mantus Anchors (Dec 13, 2011)

Remember to explain why to get the prize...


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## jameswilson29 (Aug 15, 2009)

The artist has black hair.

White replies so he is not speaking, either Red or Black is speaking. Since the hair color does not match the name, Red must be speaking and is either white or black. White is either red or black haired. Black is white or red haired. White knows his own hair color, which can't be white; the speaker can't be Black since Black cannot have black hair, so it must be Red, the artist, with black hair.


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## bristol299bob (Apr 13, 2011)

Black

none of us have a hair color that matches out name, this means that Black is not speaking. 

White responds, so that means White is not speaking. which leaves Red as the speaker, and he declared that he has black hair.


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## CalebD (Jan 11, 2008)

Given: none of us has a hair color that matches his name
The statement: "I have black hair" cannot have been made by Mr. Black.
Since the reply by Mr. White of "you are correct" implies that he did not make the defining statement, nor did Mr. Black. So the artist Mr. Red made the statement: "I have black hair". 
Given that Mr. Red has black hair there are only 2 remaining hair colors to be assigned to this colorful trio: red and white hair. Since Mr. White cannot have white hair, his hair color must be red leaving Mr. Black with white hair.

edit to add: Damn! Not quick enough!


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## Capt Len (Oct 9, 2011)

So the carver has red hair, the guy with the violin is white haired and the artist is bald and a little dingy. Edit to add .Dag nab it, even slower!


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## Mantus Anchors (Dec 13, 2011)

ok Bristol 299Bob you got it......Congrads! just private me your mailing address, phone number, email, 1000$ and your first born....
and we will send you your prize...


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## bristol299bob (Apr 13, 2011)

thanks! 

Ill throw in the second born as well


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## svzephyr44 (Jun 26, 2000)

As the first winner - the "Hook" arrived in Santa Cruz de Tenerife - already in my anchor locker - thanks
Roger


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## Mantus Anchors (Dec 13, 2011)

Ok the prize for this Riddle is a 8 lbs dinghy anchor or a Mantus Chain Hook for your size chain
PS sorry the delay, we will try to stick with Mondays as promised 

BUYING BERRIES

BERRIES ARE POPULAR WITH CRUISERS! ONE THIS LUSH TROPICAL ISLAND, A BEAUTY FULL LADY/CHAP SELLS YOU 1000 KG OF FRESH BERRIES. THE BERRIES CONTAIN 99% WATER WHEN FRESH, BUT A FEW DAYS LATER A TEST SHOES THAT THERE WAS ONLY 98% WATER, DUE TO THE DRYING OF THE BERRIES. 
WHAT DO THE BERRIES WEIGH NOW?


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## MedSailor (Mar 30, 2008)

Hmmm... I'll have a go. 

10kg must be 2% of the weight (not the water). Therefore, the berries weigh 500kg now. I think. 

If 99% by weight is water and the berries weigh 1000kg, then the water weighed 990kg and the non water portion of the berries was 1kg. 

Thus the partially dried berries (i.e. only some of the water was removed) were 98% water by weight, then we would get the following formula: 

Xkg = 98% of Xkg + 10kg 
X = 0.98X + 10 
0.02 X = 10 
X = 10 / 0.02 
X = 500

My brain hurts. My caffeine level is low. I probably missed a decimal point..... 

So the berries weigh 500 kgs now yes? That's my final answer!

MedSailor


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## Gene T (May 23, 2006)

990 kg

Gene


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## hellosailor (Apr 11, 2006)

There are so many ways to answer such a loosley put question.

The simplest solution is to go upstairs, make that one trip to the attic, and stay there while my apprentice throws the three switches in sequence. Every electrician has an apprentice.

If my apprentice has done something foolish like die on the job, I can still do the job solo. I plug 3 cheap radios into the three light bulb sockets, using the socket plug adapter that everyone has in their toolbox. #1 is tuned to classical, #3 to rock, #3 to talk radio. As I turn on each switch, I note which station starts playing.

And if all the radio stations have gone off the air, I just wait until nighfall. I look out the window while turning on the lights, and note which window, which light, has turned on with each switch.

SO many solutions, Mantus! As Aerosmith sang, Toys in the Attic! Toys!


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## yossarian (Apr 29, 2012)

970.2 kg


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## RhodesSwiftsure (Aug 5, 2007)

MedSailor looks correct by my math. It's not 1% less water, but 1% less of the total. Since so much of the total is water, to bring water's percentage down takes a lot less water:

x - 98%x = 10
x(1-98%) = 10
x = 10 (1-98%)
x = 500


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## DrB (Mar 29, 2007)

*A little Abiguous*

If you define the berry mass as the actual mass of the Berry solids (completely dehydrated), then the berry mass never changes, 10kg, no matter what the water content is. If the berry includes water mass, then MedSailor has the correct answer; 500 kg.


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## Capt Len (Oct 9, 2011)

berry pulp plus water is 1000kg 100% .99% water, rest is 10kg of pulp.So 100% of water is990kg and a 1% loss of that is 9.9kg. So the now drying berries weigh 9.9 kg less than when fresh. 990.1 kg of second class product. Top up or renegotiate the price or both. What would the average cruiser do with that many berries?


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## Capt Len (Oct 9, 2011)

If it takes a hen and a half a day and a half to lay an egg and a half, how long does it take a bantam rooster to make a hardware store from a brass doorknob


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## JulieMor (Sep 5, 2011)

Too late. I type too slow but here's how I figured it out:

99/98=1000-10/x-10
97,020=99x-10
97,030=99x
980.1=x

Add 10 for the weight of the berries
980.1+10=990.1

The answer is 990.1 KG


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## JulieMor (Sep 5, 2011)

Capt Len said:


> If it takes a hen and a half a day and a half to lay an egg and a half, how long does it take a bantam rooster to make a hardware store from a brass doorknob


Bantam roosters don't make hardware stores.


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## MedSailor (Mar 30, 2008)

Capt Len said:


> What would the average cruiser do with that many berries?


Berry wine!!!!

MedSailor


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## Capt Len (Oct 9, 2011)

Julie, you'd be surprised at what a rooster can do with the proper encouragement! Med , Ive spent many summers picking blackberries up the coast to produce 15 or 20 gallons of vino (with some considerable success) This year I'm working my way through 30 gallons of rhubarb/ orange/ginger. Welcome to sample if you come this way.


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## Mantus Anchors (Dec 13, 2011)

Very interesting responses guys! But Med Sailor takes it......
500 kg is the right answer...

1% dry stuff = 10 kg and 99%= 990 kg water
2% dry stuff = 10 kg and 98%= 490 kg water thus total weight is 500 Kg

Thank you for playing and I will see you guys Monday....


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## MedSailor (Mar 30, 2008)

Capt Len said:


> Julie, you'd be surprised at what a rooster can do with the proper encouragement! Med , Ive spent many summers picking blackberries up the coast to produce 15 or 20 gallons of vino (with some considerable success) This year I'm working my way through 30 gallons of rhubarb/ orange/ginger. Welcome to sample if you come this way.


I'll take you up on that for sure! We have tonnes of backberries down here as well. I may have to do that next year....

I'll trade you some samples of my home brewed beer. I've managed to perfect the process of brewing really good beer, with a minimum of equipment, on the boat. 

MedSaillor


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## JulieMor (Sep 5, 2011)

MedSailor said:


> I'll take you up on that for sure! We have tonnes of backberries down here as well. I may have to do that next year....
> 
> I'll trade you some samples of my home brewed beer. I've managed to perfect the process of brewing really good beer, with a minimum of equipment, on the boat.
> 
> MedSaillor


Okay, so we make wine and beer but what about the rum!


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## Capt Len (Oct 9, 2011)

Would we be obligated to calculate HST on trade and barter? Or just be scofflaws and go straight to the trade value of a liter of thunder road? (White rum to some folks) Newfies call er screech. I grow mint too.


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## Mantus Anchors (Dec 13, 2011)

The Jack in the Box
Jack weighs m
Box weighs M

So if you depress the head of the Jack and release it suddenly, it will pop up because of the spring between the Jack and the bottom of the box. How much force is required to depress the Jack so that both the Jack and the Box will jump up into the air? The mass of the Jack is m and the mass of the Box is M and the weight of the spring is negligible.
The spring is regular linear spring....

The PRIZE is MANTUS CHAIN HOOK that fits your chain size....


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## hellosailor (Apr 11, 2006)

If I recall my phsyics you are requiring or ignoring any number of unbounded assumptions about the nature of the spring itself. So with your unspoken indication that unbounded assumptions are the key to the answer, I can firmly state that no amount of force will ever be sufficient to make the box pop up into the air, as both the box and Jack are hovering in a zero-gravity LaGrange point in earth-lunar orbit. Without an operational gravity field being specified, any force "down" on the spring will simply repel the entire box, Jack and all, away from the pusher, out of the LaGrange point, and eventually to a violent death as it falls into a gravity well and plunges into the surface below, or bursts into flames en route.


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## red.sky (Jun 26, 2012)

Mantus Anchors said:


> How much force is required to depress the Jack so that both the Jack and the Box will jump up into the air?


This Force will get Jack into the air... 

altho...it might excite him instead of "depress"-ing him - is that allowed?


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## Mantus Anchors (Dec 13, 2011)

hellosailor said:


> If I recall my phsyics you are requiring or ignoring any number of unbounded assumptions about the nature of the spring itself. So with your unspoken indication that unbounded assumptions are the key to the answer, I can firmly state that no amount of force will ever be sufficient to make the box pop up into the air, as both the box and Jack are hovering in a zero-gravity LaGrange point in earth-lunar orbit. Without an operational gravity field being specified, any force "down" on the spring will simply repel the entire box, Jack and all, away from the pusher, out of the LaGrange point, and eventually to a violent death as it falls into a gravity well and plunges into the surface below, or bursts into flames en route.


I like this answer... but If the Box is made by Mantus it will land safely and survive re-entry...
No there is a solution to this problem... that can be expressed in M and m
Greg


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## bristol299bob (Apr 13, 2011)

I can confirm that Greg ships his anchor in one tough box!


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## klem (Oct 16, 2009)

m+2M


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## Mantus Anchors (Dec 13, 2011)

not yet...


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## UncleJim (Jul 27, 2009)

(m+M)/32


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## klem (Oct 16, 2009)

m+M


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## Capt Len (Oct 9, 2011)

The ratio of m/M .the acceleration of head and box are the inverse. but I don't know Jack.and to lift the box needs enough force to overcome grav. so the force must be M x9.8 meters per sec squared


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## JulieMor (Sep 5, 2011)

m-M=0


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## Mantus Anchors (Dec 13, 2011)

Guys you are so close.....


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## UncleJim (Jul 27, 2009)

(m+M)squared/32
let me try this again


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## JulieMor (Sep 5, 2011)

If the weight of the spring is negligible, yet by pushing the head down the spring causes the head to pop up, the weight of the head has to be negligible. Both now have to be nearly the same weight if the head was pushed down to completely compress the spring. And there's the big unknown. How far does the spring have to be compressed to cause the head to pop up? Of course you have to define the word "pop" when using it here. Does that mean pop up like a jack in the box, or does it merely mean making the head rise back up, regardless how quickly?

For the box to be lifted, enough force has to be created through the compression of the spring to cause both the head and the box to be lifted off the surface the box is sitting on. The force of the spring pushes the head upward at a velocity sufficient enough to stretch the spring beyond it's natural state and in doing so create sufficient stretch in the spring that the box will be lifted off the surface before the velocity of the head stops and begins to succumb to gravity and the forces of the spring returning to its natural state. 

Since the spring's weight in negligible, the weight of the box and the head would have to be negligible, barring any super-spring, space-age steel that the spring might be composed of.

The weight of all three would have to be negligible relative to the weight of any two, in other words, all are almost zero. Unless you state the head compressed the spring half way to cause it to pop up like a jack in the box, which would allow you to surmise that fully compressing the spring could cause the spring to decompress at such a rate as to lift the box off the surface as described above.

This is an answer that could be theorized in a calculus equation but I forgot most of the calculus symbols. It's been a while.


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## Gene T (May 23, 2006)

2m+M

Gene


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## Capt Len (Oct 9, 2011)

The formula should be expressed in terms of fig newtons per glass of milk. Unfortunately the variables get out of hand; temp of milk, % butterfat and whether it's really fig or those ersatz raspberry filled concoctions


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## Capt-T (Aug 14, 2011)

F = mass * acceleration (F= m*a), and weight = mass * gravity

In order for the box to "jump" off the surface it's sitting on (assuming earth with g=9.8m/s^2), the upward force, F(u), would need to be greater than the weight of the box which is (M+m)*9.8 m/s^2.

Whatever downward force, F(d), is applied to the Jack will be returned with the Jack is released. Therefore, the force applied to just overcome the weight of the Box+Jack would be F(d) > (M+m)*9.8 m/s^2

If this isn't the answer, then all I can say is F(u). ;-)


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## Capt Len (Oct 9, 2011)

The force must be greater than Mg+mg, g being = to 9.80665 meters per second squared.One must be careful to run out of cookies and milk simultaneously ; as in life or maths.


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## Minnewaska (Feb 21, 2010)

If Jack is in the box, the spring is already compressed with enough potential energy to jump both. The only force necessary is to release the catch on the spring.


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## adki110 (Feb 27, 2011)

M-m


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## Minnewaska (Feb 21, 2010)

Force > m+M


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## Capt Len (Oct 9, 2011)

The force will be greater than m.a over M If M and m are equal the the sum total will be measured in M+M s .I eat the red ones last.


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## MedSailor (Mar 30, 2008)

Remember it's a riddle guys, so things are never as they seem. I think Greg is referring to THIS kind of "Jack-in-a-box".


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## Mantus Anchors (Dec 13, 2011)

Guys sorry for the Neglect...!
Capt T is right on!!!!
Force has to be equal too or greater than (M+m) times acceleration G.
BTW Happy Thanks Giving to everyone!


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## hellosailor (Apr 11, 2006)

Force has to be...

Which radically assumes the spring can in fact absorb and return that force. In practice, the spring may be too weak to store that much energy, resulting in a total failure to launch the box.

Rather than assuming the physical properties of a spring, I maintain the box is located at a LaGrange point and it will plummet to a death in a gravity well before the box ever leaps up after Jack. A much simpler assumption.


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## Minnewaska (Feb 21, 2010)

Are these riddles or problem sets?


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## MedSailor (Mar 30, 2008)

Minnewaska said:


> Are these riddles or problem sets?


If you have to ask, Grasshopper, then you are not yet ready.....

MedSailor


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## Minnewaska (Feb 21, 2010)

MedSailor said:


> If you have to ask, Grasshopper, then you are not yet ready.....


Perhaps, but I do know the definition of a riddle:

rid·dle/ˈridl/ Noun: A question intentionally phrased to require ingenuity in ascertaining its answer.

No ingenuity required for the jack in the box, just the ability to translate mass and gravity into a mathematical equation. That's a problem set. The light switch question was a riddle.


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## Capt Len (Oct 9, 2011)

Walked up a logging road for my morning constitutional .Ran into Smokey the Bear on a similar mission. We chatted a bit about this riddle.All he said was "May the forest be with you"


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## JulieMor (Sep 5, 2011)

Minnewaska said:


> No ingenuity required for the jack in the box, just the ability to translate mass and gravity into a mathematical equation. That's a problem set. The light switch question was a riddle.


A man is standing before a portrait painting on the wall, points to the portrait and says to the person standing next to him, "Though brothers I have none, that man's father is my father's son."

Who is the person in the portrait?


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## hellosailor (Apr 11, 2006)

Is that one as old as the Sphinx?

Spoiler alert:

It is used as a test of cognitive skills because if you can rearrange the relationships to a logical order, it becomes father-son-(who is also a father therefore his son is) grandson (son of speaker).

Now for a true mystery, how is it that a random length of twine or rope can tie itself in knots, but if you held the same piece in your hands all day and flipped it around, you couldn't get it to tie itself up in knots at all?


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## JulieMor (Sep 5, 2011)

hellosailor said:


> Is that one as old as the Sphinx?


I'm reliving my childhood.


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## Capt Len (Oct 9, 2011)

That would never fly on the BC coast where the most confusing day is the 3rd Sunday of June


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## ebs001 (May 8, 2006)

hellosailor said:


> Is that one as old as the Sphinx?
> 
> Spoiler alert:
> 
> ...


That is called Speers Law: "Rope or wire left to it's own devices will tied itself in knots"


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