Science+Fair+SP

=**DOES TEMPERATURE AFFECT THE ELASTICITY OF A RUBBER BAND**=


 * Question-** How does temperature affect the stretch of a rubber band.

__**Hypothosis-**__ If the rubber band is heated then it will stretch farther.

__**Purpose-**__ The goal of this project is to investigate how the restoring force of a rubber band is different with temperature. For example if someone up north in the cold uses a rubber band we can see if it is better or worst in Florida or where there is heat

**__Materials-__**
 * Rubber bands
 * microwave/oven
 * Refrigerator/freezer
 * thermometer
 * timer
 * science notebook

Heat, cold, and room temperature


 * Entropy ** is a measure of the number of specific ways in which a system may be arranged.


 * elasticity **(strechyness)

**Radius** __**SOURCE 1**__

eHow.com []

//__**EFFECTS OF HEAT**__//

The behavior of molecules under heat would suggest that the rubber band becomes more flexible and wider. However, because of the arrangement of the particles, the band becomes smaller. It's kind of like a fence on a hill when all of the nails are in place the fence is sturdy but if you remove those nails and make the slats more movable it will eventually collapse down the hill and take up less space. This is an imperfect analogy, as the rubber band will retain its shape but the concept is close.

//__**EFFECTS OF COLD **__//

The opposite <span style="background-color: #ffffff; font-family: Arial,Helvetica,sans-serif; line-height: 1.5;">is also true. If you cool down a rubber band, it actually becomes stretchier and expands slightly. This is because the molecules actually become more organized into a more efficient stretching shape. Because the molecules are more rigid and structured, they are actually stronger. Returning to the fence analogy, a straighter and better-constructed fence will actually be far more sturdy than a shoddily built one. Again, the analogy is imperfect, because fences don't stretch very good.

<span style="background-color: #ffffff; display: block; font-family: 'Times New Roman',Times,serif; font-size: 16px;"> <span style="background-color: #ffffff; font-family: Arial,Helvetica,sans-serif;">__**SOURCE 2**__

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The relative temperature of the water will certainly have an effect on the rubber band, but the effect will vary in intensity based on a number of other factors. Among them: thickness of the band, the time in the water, and the weight of the object putting stress on the band.

In general, the elasticity of the rubber band will decrease with the decrease in temperature of the water it's soaked in. However, by placing a weighted object on the band, you are looking at two different variables. If you measure how far the rubber band stretches with a fixed weight object, you are testing elasticity. If you are testing for how much weight the band can bear before breaking, you are actually testing it's tensile strength. It's important to define this part of your experiment before proceeding. Since you asked about elasticity, I'll assume that's what you are testing.

Like most matter, the rubber contracts when it gets colder. The molecules in the rubber bad get closer together. This affects the elasticity in two ways.

1) The rubber band will not stretch as far. When the weight is placed upon it, you'll see less of a bow under the weight.

2) The rubber band will be able to sustain less weight (Back to the tensile strength thing). Since the forces holding the molecules of rubber together are stronger, they are less able to give and stretch, and the rubber band is more likely to snap.

<span style="background-color: #ffffff; font-family: 'Times New Roman',Times,serif; font-size: 16px;">__**SOURCE 3**__

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<span style="background-color: #ffffff; font-family: Georgia,serif; font-size: 16px;">Temperature can affect the elasticity of a rubber band, to a certain degree. If it is really cold, the molecules in the rubber band will tighten up. If it is really hot, the rubber band will be much more elastic.

<span style="background-color: #ffffff; display: block; font-family: 'Times New Roman',Times,serif; font-size: 16px;"> <span style="background-color: #ffffff; display: block; font-family: 'Times New Roman',Times,serif; font-size: 16px;">__**SOURCE 4**__ <span style="background-color: #ffffff; display: block; font-family: 'Times New Roman',Times,serif; font-size: 16px;">

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<span style="background-color: #ffffff; font-family: 'Times New Roman',Times,serif; font-size: 16px;"> [] <span style="background-color: #ffffff; font-family: Verdana,Arial,Helvetica; font-size: small;">a rubber band actually becomes softer and easier to stretch, when the it gets colder. The way to think of the elasticity is in terms of entropy, which is basically a measure of disorder. The universe is always moving towards a state of greater disorder. When a rubber band is stretched out, there aren't as many ways the individual molecules can arrange themselves as there are when the rubber band is not stretched. They have to be sort of lined up, instead of in a jumble. There are a lot more ways to throw the molecules into a jumble than there are to line them up. When there are more ways to arrange the molecules, the entropy is higher. So when you stretch a rubber band, the rubber band will want to contract again. Where does temperature come in? When the temperature is higher, the molecules are more excited, and want even more to be in a random jumbled state. Imagine the ICS kindergardners on a sugar high they want to run all over the place jump around, have fun anything but line up in a straight line (or nap time). This is how the molicles of the rubber band are and it makes it harder to stretch out, because it is harder to line up the molecules inside. so it is stiffer at hotter temperatures. ======

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<span style="background-color: #ffffff; font-family: 'Times New Roman',Times,serif; font-size: 16px;"> Rubber is a specific type of polymer called an **elastomer**: a large molecule that can be stretched to at least twice its original length and returned to its original shape. Early forms of rubber had gluelike properties­, especially in the hot weather like florida. when its bold, rubber had become hard and brittle. It was only after an accidental discovery b­y Charles Goodyear in 1839 that modern rubber became possible.Since then, rubber has become an important natural polymer in our modern society. We make rubber from the rubber trees or we can make it from oil and We use both types in many products. Like the Aztecs and Mayans before them, athletes and children today play with rubber balls. Of course, the most common use for rubber is in automotive tires. But pencil erasers, shoes, gloves contain the ubiquitous substance, too. In many products, rubber is added as a protective coating for either weatherproofing or shockproofing. ======


 * __SOURCE 6__**

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to a scientist, a rubber band is a chemical: a very peculiar chemical, arranged in a particular way. Lets look not at what a rubber band does but at what it is. When you consider how many different things rubber bands can do, it is surprising to learn that rubber contains just two basic elements: hydrogen and carbon. A single rubber band contains many millions of atoms joined together in long stretchy strings. But all of the atoms are either carbon or hydrogen.

__**SOURCE 7**__

<span style="background-color: #ffffff; font-family: Verdana,Arial,Helvetica; font-size: small;">Rubber bands are unusual because they are made from loosely-packed chains of atoms. These long molecules behave in a special way because of a property in physics that we call Entropy. <span style="background-color: #ffffff; font-family: Verdana,Arial,Helvetica; font-size: small;">Entropy is a way of measuring the amount of 'disorder' in a system. If all the chains are neatly lined up in rows, we say that the entropy is very low. If they are all tangled up in a mess, we say that the entropy is high. We even have ways of calculating actual numbers for the entropy. But all we need to know here is, the messier the system, the higher the entropy. <span style="background-color: #ffffff; font-family: Verdana,Arial,Helvetica; font-size: small;">Now here's an experiment you can do in your head. Imagine you have lots of long pieces of string, screwed up into a ball. They're not rolled up neatly, or coiled... just screwed up like random scribbles on a piece of paper. It's quite a mess, and the entropy is quite high. Now imagine that you grab hold of the two sides of this mess, and start to pull them apart. Something quite neat will happen... Even though they'll still be tangled up, you'll see that in the middle they all line up in straight lines pointing from your left hand to your right hand. You've created order out of a mess, and you've reduced the entropy in the system. <span style="background-color: #ffffff; font-family: Verdana,Arial,Helvetica; font-size: small;">This is exactly what happens inside a rubber band when you stretch it. The messy tangles line up a bit, and the entropy goes down. Now, in physics, when the entropy goes down, the system gives out heat, and when the entropy goes up, the system takes in heat from around it.

<span style="background-color: #ffffff; display: block; font-family: 'Times New Roman',Times,serif; font-size: 16px;"> <span style="background-color: #ffffff; display: block; font-family: 'Times New Roman',Times,serif; font-size: 16px;"> =<span style="background-color: #ffffff; font-family: 'Times New Roman',Times,serif; font-size: 16px;">**WORKS CITED** = <span style="background-color: #ffffff; display: block; font-family: 'Times New Roman',Times,serif; font-size: 16px;"> <span style="background-color: #ffffff; font-family: 'Times New Roman',Times,serif; font-size: 16px;">Frye, Matthew. "Re: How Does Temperature Affect Elasticity of a Rubber Band?" //How Does Temperature Affect Elasticity of a Rubber Band?// N.p., n.d. Web. 27 Sept. 2013. []


 * <span style="font-family: 'Times New Roman',Times,serif;">this is a good source because Matthew Frye knows what he is talking about

<span style="background-color: #ffffff; font-family: 'Times New Roman',Times,serif; font-size: 16px;">"How Does Temperature Affect Elasticity of a Rubber Band?" //<span style="background-color: #ffffff; font-family: 'Times New Roman',Times,serif; font-size: 16px;">How Does Temperature Affect Elasticity of a Rubber Band //<span style="background-color: #ffffff; font-family: 'Times New Roman',Times,serif; font-size: 16px;">. N.p., n.d. Web. 27 Sept. 2013. []


 * <span style="background-color: #ffffff; font-family: 'Times New Roman',Times,serif; font-size: 16px;">This is a good website because ask.com is run by professionals

<span style="background-color: #ffffff; font-family: 'Times New Roman',Times,serif; font-size: 16px;">"How Rubber Works." //<span style="background-color: #ffffff; font-family: 'Times New Roman',Times,serif; font-size: 16px;">HowStuffWorks //<span style="background-color: #ffffff; font-family: 'Times New Roman',Times,serif; font-size: 16px;">. N.p., n.d. Web. 30 Sept. 2013. []


 * How stuff works is a good source because it is a company run by profesionals

<span style="background-color: #ffffff; font-family: 'Times New Roman',Times,serif; font-size: 16px;">Turner, Grahame. "How Temperature Affects the Stretch of a Rubber Band | EHow." //<span style="background-color: #ffffff; font-family: 'Times New Roman',Times,serif; font-size: 16px;">EHow //<span style="background-color: #ffffff; font-family: 'Times New Roman',Times,serif; font-size: 16px;">. Demand Media, 23 May 2010. Web. 27 Sept. 2013. []


 * <span style="font-family: 'Times New Roman',Times,serif; font-size: 16px;">This is a good source because it is written by professionals

<span style="background-color: #ffffff; display: block; font-family: 'Times New Roman',Times,serif; font-size: 16px;"> White, Laurence B., Jr. "Investigating Science with Rubber Bands." N.p., n.d. Web. []


 * Besides being a master builder of paper architecture, Laurence B. White, Jr. is also a member of the Society of American Magicians. Both activities may seem unrelated, but they really reflect different facets of his principle interest: the dramatic presentation of scientific ideas. As Assistant Director of the Needham (Massachusetts) Elementary Science Center and as a popular television teacher, he has had ample opportunities to use his unique talents