Duct+Tape

=__**Duct Tape Lab**__=

Primary Authors: Ali Shaw, Troy Farsakian, Kevin Schroeder

Abstract: The goal of our experiment is to determine how much duct tape is required to hold a 17-year old student to the ground, even while attempting to jump. First, we tested the strength of a multiple pieces of duct tape of various sizes with a force prob. Then, we measured the force exerted on the ground from jumping by standing on a force scale and recording the force will we attempt a stationary jump. Lastly, we placed duct tape (one piece at a time) over our shoes in order to determine how much is needed to hold a student to the ground.

Introduction: Duct tape's widespread popularity and multitude of uses has earned it a strong place in popular culture, and has inspired a vast number of creative and imaginative applications. This is mostly because of its well-known adhesive strength. Many people have put duct tape to the test in order to find out how strong duct tape really is. Duct tape is used worldwide and has even been used in emergency situations. In fact, NASA engineers and astronauts used duct tape to repair a broken wheel fender on a lunar module. If duct tape can be used in so many different situations, then how strong is duct tape? That was one of our goals in this experiment: to find out how strong the adhesive of duct tape is. Not only that, but we took it a step further and wanted to find out how much duct tape it would take to restrain a student from jumping off of the ground.

Methods/Results: There are two necessary experiments that must be completed prior to testing how much duct tape are required to keep a student on the ground. We approached this experiment by trying to figure out how many Newton's of force it takes to rip different sized pieces of duct tape off the ground. Then, by using our data, we would compare those forces with the force of an average 17-year old student (Troy was the lucky volunteer for this experiment) in order to find out how much area it would take to hold him on the ground. Here is what we did:

First, we tested how much force it takes to lift a piece of duct tape off the ground. We attached string to the back of the duct tape that measured 5cm X 10cm and found that it took 65N to unstick and lift the piece. We then conducted this same experiment on two other size pieces of duct tape. The results are below in a table. See video for a better idea on how to set up the force probe.

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Data from experiment 1:


 * 5 CM X 10 CM || 65 Newtons ||
 * 5 CM X 5 CM || 53 Newtons ||
 * 5 CM X 2.5 CM || 47 Newtons ||

The second experiment we conducted, was conducted to find the amount of force Troy, Kevin, and I exerted while we attempted a stationary jump. To do this, we connected the force scale to Logger Pro, then from rest, we took turns jumping as high as we could. See pictures below for clarification.

Here is the data:


 * Kevin || 1624N ||
 * Troy || 1530N ||
 * Ali || 1512N ||



The final step of the experiment was to combine the results from the first two experiments, and duct tape Troy to the ground. Initially, we either made a mistake on under calculating the amount of duct tape needed to hold Troy down or the method we taped him down was not correct. Our first failure could also be attributed to both reasons.

After we realized that this method would not work, we decided to tape his feet down separately. Troy observed that taping his feet down in this method felt more difficult to jump through, but once again, he was able to jump through the tape. The math behind our amount of tape used is as follows:

The amount of force a 5 X 10 piece of tape could hold was 65 N. We found that if we double the amount of duct tape then it requires 22.6% more Newtons to lift it off the ground. With this therory in mind, we calculated that each piece of tape we used in attempt # 1 and #2 would be 61 CM long and each piece would have a holding force of 79.2 N per piece. We divided this number by Troy's exerted jumping force from experiment 2. Our predicted number of duct tape pieces was about 19.

Attempt #3: We did some recalculating and figured out that our previous calculation was wrong. We measured the strength of a 5 X 2.5 piece of tape so that we could compare that with our other data. It turns out that the 5 X 2.5 CM piece of tape had about 6 N less strength than a piece that was twice as long, but then the piece of tape that was 4 times as long had 12 N more force. Taking that into consideration, we assumed that when you double the length of the tape, you get 6 x 2^n with the letter "n" representing the number of times longer the tape is than 2.5 CM. Using this equation, we found out that it would take up to n = 6 and when we added up our numbers from n = 0 to n = 6, we found that it would take about 5 X 317.5 CM^2 in total area in order to have the required strength to keep us on the ground. Another way to think of it is: 2.5+2.5(2)+2.5(4)+2.5(8)+...2.5(64)=317.5 CM (this number represents the length of each piece. It was easier to measure the length of each piece we stuck to the ground and then afterwards figure out the area of the tape on the ground by multiplying each length by 5 CM)

With this in mind, we decided to strategically stick the tape to the ground so that its are would equal 1587.5 N or equal a length of 317.5 CM. However, we also wanted to account for the fact that our mathematics was not 100% correct. The math that we did in this experiment was purely an estimation because it would be very difficult to test the strength of larger pieces of duct tape. We also wanted to account for the fact that while restricted, Troy would have more adrenaline and would have a little bit more jumping force than usual. Because of this, we made a rough estimation and added about 100 CM of duct tape to see if that would hold Troy on the ground. There was about 204 CM of tape on the ground securing Troy's left foot and there was 207 CM securing his right foot. This gave us about 411 CM in total length and we were ready to test it out.

However, on this attempt, we tried to be very careful while putting the duct tape on the ground. We made sure that all the duct tape was only touching the ground and not overlapping over another piece of duct tape and we measured the exact amount of duct tape that was secured on the ground. We knew that this would give us much more accurate results than using a bunch of 61 CM pieces of tape.

Our calculations proved right, and Troy stuck to the ground! Here is a video of the process:

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Conclusion: Ultimately, in the end, Troy was able to stick to the ground. Enough duct tape was used to cancel out the upward force of the jump. Our third method worked the best because we took more careful measurements. We tried to eliminate human error as much as possible in the third trial. Instead of just giving a large estimate for the amount of tape we need to use and slop it on Troy's feet, we carefully and strategically placed it while taking a measurement every time. We used an 'X' method to tape the shoes down. The first two trials may have worked but human error could have take place. First of all, Troy could have been jumping with a stronger force due to the adrenaline he was feeling because he complained of being 'pumped up' during the trial. Also on the first two trials, we did not place the tape strategically. Pieces were overlapped. Luckily we figured out all the kinks just in the knick of time, and got a result! Duct tape can restrain a person from jumping!