The Bicycle Problem


An ordinary bicycle is supported lightly so that it rests on its wheels, will  move forwards or backwards, and will not fall over. It rests on a level road with the pedal cranks vertical. A piece of stout cord is secured to the lower pedal and is led to the rear of the bicycle with the cord parallel to the road. A steady pull is exerted on the cord away from the bicycle.

What happens? 
Oxfoes says one thing Cambridge another Manchester might say something else but have not been consulted yet!
HGT

so have you come to a conclusion as to what happens yet?

Provided that the chainwheel is attached to the rear sprocket (that's NOT a Merlin Sprocket by the way!)with a chain then the bike will move forwards.

wrong

fixed gear or freewheel?

it falls over?

If we assume that away from the bicycle means away backwards, parallel with the road rather than sideways parallel with the road then this will try to pull the pedal round which will try to move the bike forwards. However, you are pulling backwards so what will probably happen is that the bike will pivot on its rear wheel. The pulling of the string wants to try to make the bike go forward due to the rotation of the pedal but you pulling the string backward is stopping the bike from going forward. So if there's enough friction between the bike tyre and the road and the bottom of the pedal is not too low so that you have enough moment then the bike could pivot about it's rear wheel i.e. the handle bars would start to rise in the air. Alternatively it could just be dragged backwards - doing a sort of backwards skid if you will.

alternatively nothing may happen as the force of you trying to push the pedal forwards via a piece of string and the force of you pulling the bike backwards may be equal. 

just a few thoughts there... as you may be able to tell, this afternoon is getting rather boring.

Nothing..

Depends on the gearing.  Ratio of crank length to radius of wheel is about 1:2 (170:350 cm on my bike).  If the gear the bike is in gives less than a 2:1 ratio the bike will move forwards, otherwise it will move backwards.  Frictional losses will mean it is unlikely to move at all unless the ratio is well away from the 1:2

Am I right?

Do the pedals go round....?

I,m with BMX nothing will happen, the bike will remain static. As the cord is pulled the bike will want to go forward but the act of pulling on the string will prevent it from moving, therefore it will remain in the same place.

it wont move - too much inertia to get it going...

Can't get the bike to stay upright!

The strings snaps..

As I see a slow day at the office!

String remains on road, Some tea leaf in baggy trousers & tea cosy hat has just nicked the bike? 
So the answer, it went forwards!

assuming enough friction between the tyre and road and the cord is stout enough and no backlash in the transmission it stays still. until enough pull to pivot it on its back wheel.

Nothing

Newtons laws? to every action there is an equal and opposite reaction. 

Einstien? - its all relative; to the fact that the pedal- if it were to go round, would not move back as far as the bike wanted to move forwards - so no movement

Bike moves backwards and the pedal moves forward.

Miles is right and so in Newton.
IF Einstein had spent time on the banks of the Cam watching the Punts he might have got it right.

The one thing that won't happen is that the bike will pivot around the back wheel.  The string parallel to the road and attached to the bottom pedal will be below the rear axle.  Therefore all the rotational force will pull the front of the bike down.

The gearing is the critical point.  The issue is whether the pedal at any point in its circuit will be travelling backwards in relation to the road.  If so (and it would be a very high gearing) then pulling on the string will result in the bike moving forward a few inches, until the pedal reaches the point at which it is no longer moving backwards in relation to the road.  If the string doesn't break, that's when the bike explodes.

Just tried this experiment.

Result - Nothing happens QED

well done Miles!

I'm with the gearing men. If the gearing is low enough the bike will start to go forward but the driving force from the string will reduce to zero after a quarter turn of the pedal and will be exerting some braking force before then. So, like all silly jokes, it don't get you far.

Mike that's exactly the point.

You can tell it's snowing in the UK and here is just V Cold things are slow with Bush, Blair, Iraq et al there is not a lot to laugh about so here are few GROAN type jokes.
If you feel the need to do something even if its only pour another scotch then it will have been worthwhile! No claim is made for originality!

1. Two vultures board an airplane, each carrying two dead raccoons.   The
stewardess looks at them and says, "I'm sorry, gentlemen, only one carrion
allowed per passenger."

2. Two boll weevils grew up in South Carolina. One went to Hollywood and
became a famous actor. The other stayed behind in the cotton   fields and
never amounted to much. The second one, naturally, became known as the
lesser of two weevils.

3. Two Eskimos sitting in a kayak were chilly, but when they lit a fire in
the craft, it sank, proving once again that you can't have your kayak and
heat it, too.

4. A three-legged dog walks into a saloon in the Old West. He slides up to
the bar and announces: "I'm looking for the man who shot my paw."

5. Did you hear about the Buddhist who refused Novocain during a root canal?
He wanted to transcend dental medication.

6. A group of chess enthusiasts checked into a hotel and were standing in
the lobby discussing their recent tournament victories. After about an hour,
the manager came out of the office and asked them to disperse. "But why?"
they asked, as they moved off.  "Because," he said, "I can't stand chess
nuts boasting in an open
 foyer,"

7. A woman has twins and gives them up for adoption. One of them goes to a
family in Egypt and is named "Ahmal." The other goes to a family in Spain;
they name him "Juan." Year's later; Juan sends a picture of himself to his
birth mother. Upon receiving the picture, she tells her husband that she
wishes she also had a picture of Ahmal.   Her husband responds, "They're
twins! If you've seen Juan, you've seen Ahmal."

8. These friars were behind on their belfry payments, so they opened up a
small florist shop to raise funds. Since everyone liked to   buy flowers
from the men of God, a rival florist across town   thought the competition
was unfair. He asked the good fathers to   close down, but they! Would not.
He went back and begged the friars to close. They ignored him.   So, the
rival florist hired Hugh MacTaggart, the roughest and most vicious thug in
town to "persuade" them to close. Hugh beat up the friars and trashed their
store, saying he'd be back if they didn't close up shop.  Terrified, they
did so, thereby proving that Hugh, and only Hugh, can prevent florist
friars.

9. Mahatma Gandhi, as you know, walked barefoot most of the time, which
produced an impressive set of calluses on his feet. He also ate very little,
which made him rather frail and with his odd diet, he suffered from bad
breath.  This made him ... what?    (This is so bad, it's good)

 A super calloused fragile mystic hexed by halitosis.

10. And finally, there was the person who sent ten different puns to
friends, with the hope that at least one of the puns would make them laugh.
Unfortunately, no pun in ten did.

don't encourage him

.....Sorry, but some of them are pretty good!!

Then how about this one!
A red indian chief had three wives they lived in seperate tepees, one had a bear skin on the floor of her home, another a deer skin and the third an imported hippapotamus skin, in due course they all became preganant the wife with the bear skin had a boy, the one with the deer skin a baby girl, and the wife with the hippopotamus skin had twins- a boy and a girl, which of course demonstrates that the squaw on the hipopotamus is worth the sum of the squaws on the other two hides! Boom Boom Mt Derek. Got to fly.... If you live in Gloucestershire sorry we're low flying there today.

I've polished the bottom of the yot for the nth time ckecked the serial no's on the sails for the next regatta, WD 40'd everything -again!
So here's another one.
In Africa a man goes to see the doctor with tummy trouble he's given a piece of leather to chew and told to come back in a week, he returns 7 days later asked how he was he said, we'll i've finished the leather but I'm not any better better indeed.....the thong has ended but the malady lingers on.

A Polynesian chief was expecting a visit from the Queen, in discussion with the Governor General it was decided to hide the throne so's not to upset Her Majesty. 
After a very succesful visit the Governor General and the chief are standing around congratulating themselves, when the throne falls out of the roof (Where it was put.)
They are both killed which perhaps demonstrates that people who live in grass houses should not stow thrones!

Got any more?

yes, but i'd only incur the wrath of the moderator!

Sorry could not resist this, one maybe there should be a jokes page.  wont do it again promise

Doctor Dave had slept with one of his patients and felt guilty all daylong. No matter how much he tried to forget about it, he couldn't.

The guilt and sense of betrayal was overwhelming. But every once in a while he'd hear an internal, reassuring voice in his head that said: "Dave, don't worry about it. You aren't the first medical practitioner tosleep with one of their patients and you won't be the last. And you're single. Just let it go.."

But invariably another voice in his head would bring him back toreality, whispering:......
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>..............you're a vet."

I shall borrow this if I may, and homour in all things please its so much more interesting than shroud tension. Talking of tension.... don't even go there (Mrs Literary Agent!).......

Everybody I know who has a dog usually calls him "Rover" or "Spot". I call mine Sex. Now, Sex has been very embarrassing to me. When I went to the City Hall to renew the dog's license, I told the clerk that I would like a license for Sex. He said, "I would like to have one too!" Then I said, "But she is a dog!" He said he didn't care what she looked like. I said, "You don't understand. ... I have had Sex since I was nine years old." He replied, "You must have been quite a strong boy." When I decided to get married, I told the minister that I would like to have Sex at the wedding. He told me to wait until after the wedding was over. I said, "But Sex has played a big part in my life and my whole world revolves around Sex." He said he didn't want to hear about my personal life and would not marry us in his church. I told him everyone would enjoy having Sex at the wedding. The next day we were married at the Justice of the Peace. My family is barred from the church from then on. 

When my wife and I went on our honeymoon, I took the dog with me. When we checked into the motel, I told the clerk that I wanted a room for me and my wife and a special room for Sex. He said that every room in the motel is a place for sex. I said, "You don't understand. ... Sex keeps me awake at night." The clerk said, "Me too!" 

One day I entered Sex in a contest. But before the competition began, the dog ran away. Another contestant asked me why I was just looking around. I told him that I was going to have Sex in the contest. He said that I should have sold my own tickets. "You don't understand," I said, "I hoped to have Sex on TV." He called me a show off. 

When my wife and I separated, we went to court to fight for custody of the dog. I said, "Your Honor, I had Sex before I was married but Sex left me after I was married." The Judge said, "Me too!" 

Last night Sex ran off again. I spent hours looking all over for her. A cop came over and asked me what I was doing in the alley at 4 o'clock in the morning. I said, "I'm looking for Sex." -- My case comes up next Thursday. 

Well now I've been thrown in jail, been divorced and had more damn troubles with that dog than I ever foresaw. Why just the other day when I went for my first session with the psychiatrist, she asked me, "What seems to be the trouble?" I replied, "Sex has been my best friend all my life but now it has left me for ever. I couldn't live any longer so lonely." and the doctor said, "Look mister, you should understand that sex isn't a man's best friend so get yourself a dog."

An Irishman walks into a bar in Dublin, orders three pints of Guinness and sits in the back of the room, drinking a sip out of each one in turn. When he finishes them, he comes back to the bar and orders three more. 
The bartender approaches and tells him, "You know, a pint goes flat after you draw it; it would taste better if you bought one at a time." The Irishman replies, "Well, you see, I have two brothers. One is in America, the other in Australia, and I'm here in Dublin. When we all left home, we promised that we'd drink this way to remember the days when we drank together. So I drinks one for each o' me brothers and one for meself." 
The bartender admits that this is a nice custom, and leaves it at that. The Irishman becomes a regular in the bar, and always drinks the same way: He orders three pints and drinks them in turn. One day, he comes in and orders two pints. 
All the other regulars take notice and fall silent.
When he comes back to the bar for the second round, the bartender says, "I don't want to intrude on your grief, but I wanted to offer my condolences on your great loss."
The Irishman looks quite puzzled for a moment, then a light dawns in his eye and he laughs. "Oh, no, everybody's just fine," 
He explains,"it's just that me wife had us join that Baptist Church and I had to quit drinking. 'Hasn't affected me brothers a bit though."

Very impressed at what i started here. theses are funny and clean and cheer me up as I sit here in sno bound Scandinavia

Local parish magazine punchline to the "brothers" joke was that he had given up drinking for Lent - good joke whatever!!

Scandinavian accent required here


Man walks into a chemist in Norway and asks for a deodorant.

"Ball or aerosol?" asks the chemist

No - it's for my armits!

Thinking of A Dog named sex and this is true, a friend of mine Guy Bentink who lives at Saltash just over the bridge at Plymouth and is thus in Cornwall has a Black Labrador called "Nigger" Nigger changes his name to Snowdrop when he goes East at Exeter! "Political correctness gone mad!"
Med venlig hilsen
H

The owner of a petrol station in Essex  was trying to increase his sales, so he put up a sign showing "FREE SEX WITH FILL-UP!" 

Soon a local young man, Jim filled his tank, and then asked for his free sex. 

The owner told him "pick a number froom 1 to 10; if you pick the right number, you will get your free sex." Jim picked the numner 8, and the station owner said, "You were close. The number was 7. Sorry, no sex this time." 

A week later Jim, along with his buddy Bill, pulled into the station. Jim filled his tank, and again asked for his free sex. The station owner gave him the same story again, and asked him to guess a 
number. This time, Jim guessed 2. The station owner said, "Sorry, the correct number was 3. You were close, but no free sex this time." 

As they were driving away, Jim said to Bill, "I think that game is rigged, and he doesn't really give away free sex." 

Bill replied, "No it ain't rigged Jim. My wife won twice last week."

Seeing you are all at here is another one


A married couple having their first baby were invited to make use of a new machine that would transfer a portion of the mother's labour pains to the Baby's father. Both were happy to try it. 

The pain transfer was set to 10 percent but the husband felt nothing so the doctor increased it to 20 percent. 

The father said he still felt fine and his blood pressure was normal. He invited the doctor to kick it up to 50 percent .Still no reaction. The doctor was amazed and slowly transferred all the pain until the wife delivered a healthy baby with virtually no pain. She and her husband and the doctor were ecstatic. 

When they got home, the postman was lying dead at the gate.

POLICE WARNING 
> 
Police are warning all men who frequent clubs, parties and local pubs to be alert and stay cautious when offered a drink from any woman. Many females use a date rape drug on the market called "BEER" to target unsuspecting men. The drug is generally found in liquid form and is now available almost anywhere. It comes in bottles, cans, from taps, and in large "kegs." Beer is used by female sexual predators at parties and bars to persuade their male victims to go home and have sex with them. Typically, a woman needs only to persuade a guy to consume a few units of Beer and then simply ask him home for no strings attached sex. Men are rendered helpless against this approach. After several Beers, men will often succumb to desires to perform sexual acts on horrific looking women to whom they would never normally be attracted. After drinking Beer men often awaken with only hazy memories of exactly what happened feelingthat "something bad" occurred. At other times these unfortunate men are swindled out of their life's savings, in a 
familiar scam known as "A Relationship." It has been reported that in 
extreme cases, the female may even be shrewd enough to entrap the 
unsuspecting male into a longer-term form of servitude and punishment 
referred to as "Marriage."  Apparently, men are much more susceptible to this scam after Beer is administered and sex is offered by the predatory females. 

Please forward this warning to every male you know. If you fall victim to this insidious Beer and the predatory women administering it, there are male support groups with venues in every town where you can discuss the details of your shocking encounter in an open and frank manner with similarly affected, like-minded guys. For the support group nearest you, just look up

 
"Golf Courses" in the yellow pages.

The Cat and the Fly
See there is this fish and he is  looking at a fly hovering over the water "If that fly would drop six inches I could jump out and catch it."
There is this bear on the bank of the lake and he is saying " If that fly would drop six inches then the fish would jump out to get it and I could grab the fish."
There is a hunter in the forest taking aim at the bear. "He says "If that would drop six inches then the fish would jump aut of the water the bear would reach out for the fish, the bear would come out into the clear and I could shoot it!"
There is a mouse behind the hunter. He is looking at the hunters cheesse sandwich. He says " If that fly would drop six inches the fish would go for the fly, the bear would go for the fish, the hunter would put down his cheese sandwich and go to shoot the bear and I could grab the cheese sandwich."
There is a cat standing back from the mouse. She is saying " If that fly would drop six inches then the fish would jump to get the fly the bear would go for the fish the hunter would put down his cheese sandwich to shoot the bear the mouse would run for the sandwich and I could grab the mouse in a second!"
Then it happened!
The fly dropped six inches.
The fish jumped up and got the fly!
The bear reached out for the fish!
The hunter put down his cheese sandwich and shot the bear!
The mouse ran and picked up the sandwich!
The cat lunged for the mouse, missed and ended up in the water!

The moral?

Everytime a fly drops six inches a pussy gets wet!

On the cruise ship, the conjuror is in the middle of his act when his best disappearing trick is ruined by the parrot behind the bar, which suddenky squawks out 'it's behind his back, it's behind his back'.

The conjuror pulls himself together and presses gamely on, only to have a second trick spoilt.  'It's up his sleeve, it's up his sleeve'.

Sweating slightly, the conjuror tries one last time and just as he reaches the climax, the ship hits a rock and twenty minutes later he finds himslef alone on a life raft except for the parrot, which is perched at the other end.  There is a long pause, and then the parrot says 'alright, I give up, where d'you put the bloody ship'.

you guys need to get out more