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I had planned to use a Newton pull scale to measure the force to pull the ice cubes across the different grades of sandpaper. But, I realized the margin of error was greater with this method, so I decided on using a more reliable method of a pulley system. Also, I planed to make Popsicle sized ice cubes and to tie a string around them. Again, the margin of error was greater with smaller ice cubes rather than with much larger ice "chunks" which are easier to measure the force to move them. The "eye hook" was also another improvement that would allow the string to be easily fastened onto the ice chunk. This lab is pretty simple to perform, but I have found that possessing the right tools and resources will probably lessen the burden of uncertainty.

First, the ice chunks must be made. Ice chunks take a while to form, so the day before the actual experiment I placed them in the freezer. I set up a little contraption to make my ice chunks (see fig. 2). I filled the Tupperware containers up with water and cut a piece of cardboard that would just slightly cover the top of the Tupperware. Then, I drilled a hole in the middle and placed the eye hook in the hole. This allowed the hook’s "eye" to stay out of the water and to make sure that it was straight as possible. I made two ice chunks. It is good to experiment with more then just one of the same object. Another ice chunk might be different than another, and it helps to have another one in case of an accident. I let them sit in a freezer for about twenty-four hours before I used them. When they are quite sticky and hard, now the experiment can begin. Be careful when taking the ice chunks out of the Tupperware. I broke one of my Tupperware containers because I was too rough with it. Work the ice chunks out easily until they are out. Do not force them.

Now that the ice chunks are formed, keep them in the freezer and move onto the flat surface that the experiment will take place. I used my kitchen table, which is fairly level and free of any foreign particles to interfere with my project. First, clamped a small pulley that consisted of a wheel and a clamp to the edge of the table. I continued be taping one of the six different grades of sandpaper to the table, to keep it from moving. When I first performed the lab, I noticed that the ice chunk was tipping over because the string was pulling it in an angle. The hook in the ice was about an inch higher than the pulley. To fix this problem, I invented a system that would allow the ice to be pulled uniformly across the sandpaper (see picture 1 and 2). For this, I raised the clamp height by clamping it to a piece of scrap wood and then by placing two more scrap pieces under that. I then clamped the three pieces of wood plus the clamp onto the table with two hand clamps (see picture 1 and 2). But, even with this improvement, the ice still tipped over. I finally noticed that the Tupperware containers were flanged at the top. This made the sides of the ice tapered. So, I placed a small drinking glass between the ice chunk and the pulley so that the string would be at an angle similar to the angle of the tapered ice. Next, I finished the setup by small paper cup and drilled two holes in the top to allow the string to be threaded through it and tied above it (see fig. 3). I again came across difficulties with this cup. After trying the first ice chunk, I noticed that I had filled up the cup before the ice broke the friction. So, I retrieved a bigger, stronger 16 ounce plastic cup to hold the heavy sand.

After I solved the problems, I then started to record data. Remember that time is an utmost importance here, because ice melts when exposed to room temperature. Between the actual sliding and the measuring of the ice chunks, I placed them into the freezer so that they would not melt. I begin by using a gram scale and measuring the mass of block #1. I then rushed over to my setup and placed the chunk onto the lowest grade of sandpaper. Next, I put the loop of the string over the hook and placed it on the pulley. I kept the distance between the ice chunk and the pulley the same all through the experiment. After everything was in its place, I started to pour sand into the cup by spoonful. I kept pouring sand into the cup until the ice chunk finally broke its bond with the sandpaper. I took the loop off of the hook and measured the mass of the cup plus the sand. I hurriedly put chunk #1 back in the freezer and took out chunk #2. I repeated the same process as I performed with chunk #1. After I slid both of the chunks across the same grade, I switched the grade with the next highest grade. Again, I took out the chunk and weighed it and rushed over to the table and started the procedure a third time. Once it started sliding I would measure the mass of the sand and the cup and put the chunk back into the freezer. I did the same thing for six different grades of sandpaper. Unfortunately, I noticed by the last grade, that both ice chunks were becoming wet and slippery. I continued the experiment, though, but I figured that I would let the ice chunks sit in the freezer for another day and perform the whole process over again the next day, except to swap the order of the grades. So, the next day I started with the highest grade of sandpaper and worked down.