Partly busted the mythbusters tried to pull the books apart with human power, first attempting to do so on their own and then bringing in ten other people which included tory and kari in a separate. Since most people do not have two phone books sitting around, we will show you how you can do the same experiment with sticky notes. The aim of our experiment is to illustrate the friction force in a dramatic way and to simplify the tedious job of interleaving a large number of book pages. This is exactly what the team investigating the friction of phone books did.
Coefficients of static friction for a few common materials. Try variations on this, crumpling the paper for instance. It is impossible to separate two phone books interleaved pagetopage due to the massive amount of friction between the 800 pages of each book. A long time ago, a phone book was a book that had an index of phone numbers for everyone in your city. Physicists solve the mystery of interleaved phone books.
They ended up needing two tanks to pull the phone books apart against the resistance of friction. Interlaced pages of a book will stick together like glue. But try dropping the sheet of paper and the phone book together with the sheet of paper on top of the book. The more pages you put together, the bigger the area and the more friction you create. Friction, good people, is a wonderfully powerful force.
This phenomenon is commonly demonstrated with phone books. Does interweaving the pages of two phone books create an unbreakable bond. Explanation because of friction, it is difficult to separate the phone books. Friction is the resistance that one surface or object encounters when moving over another according to a dictionary definition i read. In fact, if the experiment is done at a larger scale using two phone books, those phone books can even be attached to a crane to lift the weight of an entire car. As a part of the the az science experiments for kids series hosted by frogs and snails and puppy dog tails, my son and i conducted a series of cool experiments that explored friction.
There are sliding friction experiments, a phone book friction experiment, a way to make rice stick together, an experiment to create frictional heat, and lots more friction experiments for all ages. Cool experiments with friction for kids jdaniel4s mom. The suggestion that two interleaved phone books cannot be pulled apart is more complex than it seems. They attempt to pull the two phone books apart and measure how much force it takes to do so. Mythbusters phonebook friction tv episode 2008 imdb. There are sliding friction experiments, a phone book friction experiment, a way to make rice stick together, an experiment to create frictional heat, and lots more friction. Apr 07, 2015 friction is the resistance that one surface or object encounters when moving over another according to a dictionary definition i read. If there are 999 pages in total in contact with each other, the friction between the pages is equal to 500 times the friction between one book and a table. The force of friction and the weight of the pages combine, tightly binding the phone books together and making separation impossible for a. In this phone book case however the area is increased by interleaving many friction surfaces so that the force is applied in series to all the surfaces without the corresponding decrease in pressure.
Abstract in this paper we describe a simple alternative to the telephone book friction experiment, a classic demonstration where a small force generated for example by the bending of the outer pages is amplified by the large number of surfaces in contact, resulting in a huge maximum static friction force that has to be counterbalanced in order to separate the books. What are the effects of balanced and unbalanced forces on the phone books. Scientists figure out why interleaved phone books cant be. When tempers flare during a particularly complicated myth, jamie offers up a simple solution. Friction is a force that must be overcome before an object can move across a surface. People have tried pulling two interleaved phone books apart by playing tugofwar or even attaching them to cars or tanks driving in opposite directions. Sticky notes are much smaller than phone books, so they should be easy to pull apart, right. Can you lift a car using two interleaved phone books. Aug 20, 2018 in this paper we describe a simple alternative to the telephone book friction experiment, a classic demonstration where a small force generated for example by the bending of the outer pages is amplified by the large number of surfaces in contact, resulting in a huge maximum static friction force that has to be counterbalanced in order to.
The backoftheenvelope answer is friction between the pages. Friction slows the ball to a stop while preventing your feet some sliding out from under you. One of the sessions focuses on different types of friction. Each page in contact has the friction caused by the weight of the pages above it pushing down. People are then invited to pull the directories apart. Many people are familiar with the friction enigma of two interleaved phonebooks, in which all of the pages of two phonebooks are overlapped, one by one, with the books spines facing.
Dec 09, 2015 many people are familiar with the friction enigma of two interleaved phonebooks, in which all of the pages of two phonebooks are overlapped, one by one, with the books spines facing. It would have been convenient to simply say that the unbreakable phone books are caused by friction between the pages and move on. Because of friction, it is difficult to separate the phone books. What a cool and easy way to experiment with friction. I thought that in the phone book example, the normal foce acts through multiple surface areas, so the total normal force through all the surface areas n x normal force. Aug 17, 2015 of course, friction only occurs when two surfaces are pushed together, and experimenters often explain that gravity is the force that pushes the pages together in these experiments. Why is the normal force not divided for every friction plate since there are multiple point of contacts. It is an old barroom trickmaking a nexttoimpossible task seem easy. Even a small number of interleaved pages can result in a surprisingly large amount of friction, making the sticky notes impossible to pull apart. Shuffle two phone books together like a deck of cards. We wanted to measure whether friction increased or decreased with different surfaces, so i placed various materials on the bottom of the ramp during each round of racing. It crops up in the automotive word all the time, be it associated with tires, brakes and engine internals, or. It demonstrates that all objects probably fall at the same rate apart from air resistance which is what uses up a lot of fuel in a car.
In this lab, you will make some basic measurements of friction. It would have been convenient to simply say that the unbreakable phone books are caused by friction between the pages and move on, but that didnt tell the. Friction plays a crucial role in the development of roller skates as well as the means with which you choose to stop. Supposing that the static coefficient of friction between the pages is the same as that between a book and a table, than in this case the friction force between the books equals 1 1999. People have tried pulling two interleaved phone books apart by playing tug. Physicists solve the mystery of interleaved phone books mit. Using a model that reproduces the traction and friction forces involved, researchers have shown that when the spines of the interleaved phonebooks are pulled on vertically, part of the vertical. When i was ready to do this i got some help to try to pull on the books to put more pressure on the phonebooks. Jun 20, 2017 test which surfaces create more friction, see how strong friction is, learn how to reduce friction, and even discover the side effects of friction. Phone book paper is on the rougher side, probably 0.
Solutions the discovery channels mythbusters recently conducted an experiment to find out how much force is required to separate two interleaved phone books. Phonebook friction podcast home all science fair projects should aim to follow the scientific method, which is a specific sequence of steps to take when experimenting to prove some hypothesis. In the process i revived the conundrum of phone book friction. Friction is the reason you cant roll a ball for eternity with one toss, but its also what enables you to run as you press your feet against the ground. Oct 22, 2015 phone book friction, from mythbusters the enigma of the two interleaved phonebooks pdf, from cornell university library slippery science. And then kari, grant and tory test a fishy tale of hollywood pyrotechnics with their own big bang theories. Table 1 shows the static friction coefficients for some common materials. Will tory and kari successfully pull apart two phone books in 30 minutes without breaking their teeth. Once the pages are interlaced hold the ends and try to pull the pages apart. Inseparable books experiments steve spangler science. A simple alternative to the phone book friction demonstration. Please practice handwashing and social distancing, and check out our resources for adapting to these times. For most paper, the coefficient of friction is in the range of 0.
View homework help phone book friction presentation. How to do a friction science experiment science experiments. Find out jamies idea of a great name for a baby, as well as his preferred title for a romance novel should he write one. The trick apparently also works pretty well with reasonably thick magazines.
Dec 16, 2015 using a model that reproduces the traction and friction forces involved, researchers have shown that when the spines of the interleaved phonebooks are pulled on vertically, part of the vertical. Phone book friction a popular science demonstration shows that when you overlap the pages of two phone books, they are nearly impossible to pull apart. A plain block of wood and a block of wood with sandpaper on. Then i pulled on the first try where i put 8 pages or less for the total amount of pages on these inner twined i used 1 by 1 the books didnt come apart. There are sliding friction experiments, a phone book friction experiment, a way to make rice stick together, an experiment to create frictional heat, and lots more friction stay safe and healthy. See the bibliography and search the internet for phone book friction and you will find plenty of videos showing the experiment. A pair of cars also failed at pulling the phone books apart. The aim of our experiment is to illustrate the friction force in a dramatic way and to simplify the tedious job of interleaving a large number of book pages, by using the minimum number of sheets. The force of friction and the weight of the pages combine, tightly binding the phone books together and making separation impossible for a single person. Virtual reality technology lets mom reunite with her deceased child. In this paper we describe a simple alternative to the telephone book friction experiment, a classic demonstration where a small force generated for example by the bending of the outer pages is amplified by the large number of surfaces in contact, resulting in a huge maximum static friction force that has to be counterbalanced in order to separate the books. Friction is the force that opposes motion when two surfaces are in contact. First you will measure the coefficients of static friction between several combinations of surfaces using a heavy block and a set of hanging masses.
Researchers explain why its nearly impossible to separate. By overlapping all the pages in each phone book, you created a lot of friction. With jamie hyneman, adam savage, tory belleci, grant imahara. It is impossible to separate two interlocked phone books due to the massive amount of friction between the 800 pages of each book. Phonebook friction podcast home all science fair projects should aim to follow the scientific method, which is a specific sequence of steps to take. Missouri man finds stacks of family photos and reunites them with their owners. The pages of the sticky note pads are held together by friction.
Test which surfaces create more friction, see how strong friction is, learn how to reduce friction, and even discover the side effects of friction. For this experiment, each child chose a matchbox car. I made a ramp out of foam core and poster board, leaning one against a small stool for an angle. A famous demonstration of the counterintuitive power of friction involves two telephone directories with their pages alternately interleaved. Friction experiments are some of the easiest, inexpensive, and most enjoyable for kids. Phone book friction, from mythbusters the enigma of the two interleaved phonebooks pdf, from cornell university library slippery science. Below are my favorite and super cool friction activities for kids. The mythbusters tried to pull the two phone books apart with human power, which was unsuccessful. Sep 26, 2015 one of the sessions focuses on different types of friction. Physics forces friction adam and jamie have bound two phone books together by interleaving their pages. Phone book friction justin lazaro, tarissa miller, john biehle.
A popular science demonstration shows that when you overlap the pages of two phone books, they are nearly impossible to pull apart. If you do not have two phone books sitting around, you can do the same experiment with sticky notes. On this episode of mythbusters adam and jamie take a fan mail film and use it to dial in on a phone book fable. Why cant two interleaved phone books be pulled apart. According to legend, if you interweave the pages of two phone books it is nearly impossible to pull them. Az 4h stem at home cooperative extension the university. For two books of pages each there are 1999 pagesurfaces in contact.