Super Fantastic Ice Melting Apparatus Expedition 

By Charlie Ford & Travis Gamache

 

Table of Contents

Introduction    Problem    Review of Literature    Hypothesis    Materials    Set-up    Procedure    Data & Graphs                 

Visuals of Tests    Conclusion & Analysis    Related Links    Bibliography   Return To Research

 

Introduction

            Everybody knows that ice melts when temperatures reach 32 degrees Fahrenheit or higher.  But can adding weight to the ice affect how it melts as well?  The weight affecting ice melt can be seen in many different things, such as glaciers. According to one website, As snow layers accumulate and gather weight, the pressure builds up on the bottom layer. This causes the bottom layer of ice to melt and it becomes soft and pliable. The melting of the ice due to pressure and its refreezing is called regelation”(https://www.cresis.ku.edu/education/iibLessons/iib009.pdf).  The somewhat melted ice gets pushed out to the edges and the glaciers moves a little bit thus continuing regelation.  Pressure Melting causes the ice to melt. The Pressure Melting point is when the pressure on the ice is so great that it eventually ends up melting the ice.  LeChatelier’s Principle is a good example of this, it states, “that when a system is in equilibrium, any external changes that try to take it out of equilibrium will cause the system to adjust in a way to counteract that change” (Nelson 2007).  This is like applying weight to ice. Water fills a smaller volume than ice, so it lowers its melting point allowing more ice to become liquid filling in the extra space.  Studies have shown that a certain amount of pressure can cause pieces of ice to start melting.

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Problem

          The purpose of this experiment is to find the relationship between the amounts of weight added to a copper wire resting on a piece of ice and the time it takes to cut through the ice.

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Review of Literature

 Brent Nelson a Ph.D. Student at UC Berkley states, “If you increase the pressure on the ice the ice-water system wants to try to lower it again. It can do that by making itself fit into a smaller volume. But since water fills a smaller volume when it's liquid, rather than solid, it will go to a lower melting point -- allowing more solid to become liquid” (Nelson 2007).  Because of this we believe that if the ice is being pushed on with a weighted wire that the ice is going to end up melting because its going to be splitting the ice and its going to melt to fill in the gap the wire has created. 

Also thanks to the studies from, Drake, L.D, and Shreve, R.L we know that, “The motion of wires pulled transversely through ice has long been explained in terms of pressure melting at the front of the wire and regelation behind it, the speed of the process being controlled by the rate of conduction of the heat of fusion through the wire and the ice”(Drake, Shreve).  Because of this we learned that the weight from the wire would cause the ice to cut in half do to pressure melting.  We also learn that refreezing of the ice behind the wire is called regelation.

Cresis.ku.edu also goes into some detail about this idea of regelation.  It is something that occurs often in glaciers while they are moving.  The website states, “ As snow layers accumulate and gather weight, the pressure builds up on the bottom layer. This causes the bottom layer of ice to melt and it becomes soft and pliable. The melting of the ice due to pressure and its refreezing is called regelation”(https://www.cresis.ku.edu/education/iibLessons/iib009.pdf).  This information tells us that the wire should be somewhat frozen into the ice after it has cut partially through the ice.

Overall the wire should cut through the ice due to weight causing pressure, which will melt the ice due to pressure melting.  The wire should also be refrozen into the block of ice due to regelation.

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Hypothesis

          We believe that graphically (with mass as the independent and the time it takes to cut the ice cube as the dependent) our results will be a downward slope.  The more mass added to the wire the more quickly the ice will be cut.  We will only go so high in weight because eventually the ice cube won’t be able to take the weight and our data will not be accurate.

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Materials

          The Materials we used were: a piece of wood approximately 10 ½ inches long, another piece of wood approximately 5 ½ inches long, a strip of 2mm copper wiring,

a Malleable Iron Vice Clamp, multiple Duralex LYS Small Glass Bowl (Or something similar), 1 Teaspoon, water, a freezer, a stopwatch, 2 screws, 4 2.5lb weights, 2 5lb weights, 2 10lb weights, 1 hook screw, a saw,  some sand paper, any bowl to catch the water drops, and a room at a constant 69 degrees Fahrenheit.

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Set-up

          We used four of the same Duralex Small Glass Bowls to ensure that each ice cube was almost exactly the same in size.  We filled each one of these glass bowls up with 6 teaspoons of regular tap water.  This would also ensure that the water would expand similar and there would not be any huge differences in our ice cubes.

            We also found an area that was not affected by any drafts of wind and the room temperature was able to be measured and would be the same through out the test.  We used a room that was around 69 degrees the whole time to make sure that the room temperature did not affected the melting time of each ice cube.

            For the apparatus itself we used two pieces of wood.  One piece was approximately 10 ½ inches long while the other one was 5 1/2 inches long.  We also used a piece of copper wiring.  This can very in length because it does not affect the cutting through the cube.  However, it has to be short enough that the second piece of wood is not touching the ground.  We then proceeded to screw two holes in the shorter piece of wood approximately 1 inch away from either side.  After this we screwed the screws into the bottom of the piece of wood and half the screw was still showing (the length of screw showing will vary upon the length of your wire).  After this we screwed another hole in the middle of the small piece of wood again and put a hook screw in the bottom of it to hang the weights.  We then screwed holes completely through the smaller piece of wood to allow the cooper wiring to attach to the screws.  We then wrapped the remaining copper wire to the exposed screw heads and now he had the smaller piece of wood dangling from the copper wire.  This would give us somewhere to put the weights.

            Now with the larger piece of wood we cut two slits width wise approximately 2 inches in from the end.  This allowed a place for the copper wire to hang.  Make sure that the slits are not to close; otherwise, the piece of wood could break under the weight (slits can vary in width and length they just have to allow the wire to be able to cut through the ice).  We then sanded down the middle in between the slits to make sure that the wire could cut completely through the ice block.  This also made it easier for us to tell when the wire had cut through the ice.  We then vice clamped the piece of wood to a sturdy surface and hung the apparatus up.  We then added different weights to the bottom piece of wood.  Then we took a piece of ice out of the freezer and draped the copper wire with the weights on the bottom over the top of the ice cube and recorded how long it took to melt the ice with each weight.

 

 

 


 

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Procedure

    First read the set-up to learn how to build the apparatus and freeze the ice. Then start off with two trials with no weight and only the wire draped over the piece of ice to get a control time.  Proceed by starting with 2.5lbs and time how long it takes the weight to cut through the ice block in a 69 degrees Fahrenheit room.  Do this twice.  Then add another 2.5lbs so it is at 5lbs and time how long it takes 5lbs to cut through the ice.  Do this twice as well.  Then create more ice with 6 teaspoons of water in the Duralex containers and let it sit in the freezer for 45min to 1hr depending on the temperature of the freezer (just make sure the ice is solid). Then add another 2.5lbs to the 5lbs making this weight 7.5lbs and time how long it takes this weight to cut through the ice.  Do this test twice as well.  Keep adding 2.5lbs to each previous weight until 22.5lbs having two trials for each weight and repeating step 4 whenever you run out of ice.

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Data And Graphs

 

 

 

                           Data Files (text - Tab delimited)

 

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Visuals of Tests

1 2 3

 

 

In Picture one the wire has just been placed onto the ice. 

In Picture two the wire has slowly been cutting through the ice. 

In picture 3 the wire has completely cut through the ice.  Regelation has somewhat occurred.

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Conclusion and Analysis

Our experiment and data that was produced from our experiment all supported our hypothesis.  We believed if the weight was to affect the rate at which the wire would cut through the ice, than the more weight added the quicker the wire would cut through the ice.  We immediately noticed the time decrease from 0 lbs to 2.5 and it had a continuous downward trend after that. The averages were always constantly less than the one before it, however there was no constant change between them.   We believe that this decline in time will always appear no matter what realistic conditions this experiment is tested in, however we believe that more accurate could have been obtained if there were less errors.

            We noticed that every once and a while one of the tests with a heavier weight would take longer than one of the tests with a lighter weight.  Multiple different things could cause this.  One of them may have been that when the wire was applied earlier it was at a warmer temperature than later, thus allowing the wire to cut through the ice much quicker.  Then later the wire would be colder and that’s why even though one test had more weight it would still cut slower because the wire had cooled off from previous tests.

  Another error that could have been eliminated with a more scientific setup is measuring of the water.  Being able to measure the water to an exact amount every single time without human error would make that each ice cube was exactly the same in size. This would allow for a much cleaner and accurate sense of data because every ice cube would be exactly the same.

 Another cause for error is that the wire was not placed on the exact same spot on the ice cube as the previous wire was. If there was a way to put the wire in the exact same spot there would be a much cleaner set of data.  Also by being able to place the wire at the exact same spot every time, there is a defined thickness of ice that the wire is cutting through and there is not the problem of the wire cutting through a thinner section of ice.  Because of the inability to place the wire on the same spot as the wire before it there was the possibility that the wire was not cutting exactly the same amount of ice.

There was also the possibility that the room we were melting ice in may have been of by a tenth of degree or less.  We were only able to find out the room temperature by the thermostat and there was no way of knowing the exact degree of the room besides an exact whole number.  If the experiment were done in a controlled temperature down to a tenth of a degree there would most likely be a more accurate set of data.

Finally there was also a level of human error involved.  There was no way to stop and start the timer and the same time every single time.  The reaction time to stop the timer varied from each ice cube because some made lots of noise before the wire fell while others were silent up to the drop.  We were never able to start and stop the time exactly, therefore adding a second or two each way.

Overall, our data produced results that we believed would occur.  We believe that even though there were most likely errors in our set up, not matter what the set up was there would be a constant downward trend in time as the weight was going up.

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Related Links

"Can You Melt A Glacier With Pressure?". A very basic set up for this experiment.

 

 "Why Does Increased Pressure Lower the Meting Point of Ice?".  An explanation to why ice melts under pressure by a UC Berkley Student.

 

"Pressure Melting and Regelation of Ice by Round Wires". A similar study discussing pressure melting.

 

"Glaciers".  An in-depth look at glaciers.

 

"Snow and Glacier Hydrology".  Facts and information about the movement of glaciers.

 

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Bibliography

 

"Can You Melt A Glacier With Pressure?". October 28th, 2007 <https://www.cresis.ku.edu/education/iibLessons/iib009.pdf>.

 

Nelson, Brent. "Why does increased pressure lower the melting point of ice? Can we use the First Law of Thermodynamics to explain?". Physicslink.com. October 28th, 2007 <http://www.physlink.com/education/AskExperts/ae132.cfm>.

 

"Pressure Melting and Regelation of Ice by Round Wires". Proceedings of the Royal Society of London. Series A, Mathematical and Physical Sciences, Volume 332, Issue 1588, pp. 51-83. October 28th, 2007 <http://adsabs.harvard.edu/abs/1973RSPSA.332...51D>.

 

Renton, P. "Glaciers". USGS. October 28th, 2007 <http://www.ufrsd.net/staffwww/stefanl/Geology/glacier/index.htm>.

 

Singh, Pratap. "Snow and Glacier Hydrology". October 28th, 2007 <http://books.google.com/books?id=0VW6Tv0LVWkC&pg=PA497&lpg=PA497&dq=glaciers+melting+due+to+pressure&source=web&ots=8SjD2x0L-q&sig=BTFVYg4xnpjCOwKEeaTaY2FbRcc - PPP1,M1>.

 

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