Lab 2: Scientific Method

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  Posted by Francesca Lingo on February 8, 2021 at 5:39 pm

  Over the next 1-2 days, take some time to observe your surroundings (home, nearby park, street, etc.) and make note of anything that stands out. Keep in mind that your observations are not limited to what you can see and may include smells, sounds, tastes, and touch or feeling (hot/cold, soft/hard, etc).  Do you see anything that you can\’t immediately explain, something that causes you to pause and ask, \”I wonder why….?\”

  For the purpose of this discussion, we will work together to solve this \”problem\” using the scientific method. Your goal is to find a solution that will stand up to the review of your peers.

  1. Describe your observation. Provide sufficient detail (or photos if needed) so that others in the discussion can visualize the problem you see.
  2. Ask a question about your observation for which you do not know the answer. This question will usually include the words \”how\” or \”why\”. Note that if you have trouble forming an initial question, you might want to consider a different observation.
  3. With your question in mind, make 2-3 additional observations that you believe will help you answer the question.
  4. Go ahead and try to answer your question. The answer is your hypothesis and it should come in the form of a confident statement, then you should justify your statement with your observations.

  When you have completed these steps, write a paragraph to summarize your \”research\” and post your research to the discussion board. You should use formal language and grammar (no text-message speak), and the paragraph should clearly explain identify: 1) Your research question, 2) your observations 3) your hypothesis, and 4) how you tested your hypothesis, 5) your results and conclusions.

  After you have submitted your post, return to the discussion board, and review the \”problems\” that your classmates have solved. Post a reply to a minimum of 2 different problems that were \”solved\” by your classmates. In your reply, consider the following:

  Do you agree with the author\’s conclusions?  If so, explain what evidence you found to be the most compelling or conclusive. If not, explain why you are not convinced and suggest some additional observations or tests that could be used to address any lingering questions and reach a more defensible conclusion.

  Based on the author\’s initial results, what are some new questions that you might ask?

  Due Dates

  Etiquette 

  When posting replies, please be considerate of your peers. The discussion is intended to promote a collaborative learning environment, so be careful of your tone and refrain from inappropriate language or personal attacks. You may challenge others if the intent is to facilitate growth, but do not demand, harass, or embarrass. Encourage others to develop and share their ideas.

• BYUNGJUN SHIM

  Participant

  February 13, 2021 at 10:24 am

  Why ice is slippery?
  I was walking to the grocery when I saw a guy slip on ice. Although I knew that ice was slippery, I didn’t know why it was slippery even though ice is solid and not greasy. I thought it was slippery because the heat melts the surface of the ice, creating a thin layer of liquid water. Subsequently, I came back home and place a cube of ice on my hand. As I expected, the ice melted creating a thin layer of liquid that became slippery. However, there was a huge problem I overlooked. The weather was very cold outside and the guy was wearing boots. It is hard to transfer the heat to the ice when wearing boots. Ultimately, it was the pressure that melted the ice instead of the heat. Water expands when it freezes but the pressure tries to undo the expansion and instead melts the ice that makes ice slippery.

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  David Sliva

  Participant

  February 13, 2021 at 5:10 pm

  Why do trees shed bark?

  When I was going for a walk, I noticed that most trees were shedding at least a little bark. This led me to wonder why. I noticed that that (depending on the tree), the bark that was peeling off was darker than the parts that weren’t peeling off. I also noticed that it was drier, and often flakier than the rest of the tree. The third observation that I made was that smaller and larger trees often had less bark peeling off. This led me to believe that trees shed their bark because the bark would have to stretch as the tree itself gets wider (which would explain why medium-sized trees were more prone to peeling, and why the bark that was peeling off was drier and more brittle). I believe that the peeled off portions were darker than the rest of the wood because they were less flexible, causing them to peel away from the wood, meaning they’d receive fewer nutrients, causing them to dry (leading to an increased concentration of tannins, thereby darkening the wood).

  I tested my hypothesis by peeling off three pieces of bark from a tree that was recently cut down. One piece of bark was almost completely peeled off, the second looked like it was about to start peeling off, and the last was attached to the tree quite firmly and took some effort to peel off. I compared their flexibility by bending them around an aluminium beverage container. Unsurprisingly, the portion that was about to peel off broke rather quickly (though not as quickly as the completely peeled off piece), whereas the normal bark was able to be wrapped around the container.

  The results of this experiment led me to conclude that my initial hypothesis was correct. One potential limitation of this test is the use of a dead tree, however, it was the best option considering that harming a living tree would be environmentally harmful. Despite this limitation, the most likely explanation for bark shedding is still the tree’s expansion.

  (edit: forgot to include experiment and conclusion)

  • This reply was modified 3 years, 8 months ago by David Sliva.
  • This reply was modified 3 years, 8 months ago by David Sliva.
  • This reply was modified 3 years, 8 months ago by David Sliva.
  • This reply was modified 3 years, 8 months ago by David Sliva. Reason: (edit: forgot to include experiment and conclusion)

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  David Sliva

  Participant

  February 13, 2021 at 5:57 pm

  I agree with these conclusions, seeing as water freezes at 0 degrees Celsius when the pressure is 1atm but has a lower freezing point at higher pressures (as evidenced by water’s phase diagram). The most convincing evidence was the test involving holding an ice cube to determine if it would be more slippery if it melted. It might be a good idea to try redoing the experiment with a cold object and use pressure instead of heat to melt the ice as a better proxy for the boot, which would also be cold in this case. Based on these results, I’d be interested to know how the presence of pollutants in the air impacts how slippery the ice in that area is.
  BYUNGJUN SHIM

  Participant

  February 14, 2021 at 1:24 pm

  I agree with David that trees shed their bark to become a bigger tree. The most compelling observation was the third observation ” that smaller and larger trees often had less bark peeling off.” It would be great to experiment with different kinds of dead trees.
  Saundarya Sharma

  Participant

  February 14, 2021 at 4:22 pm

  Why does snow crunch when you step on it? At what temperature does it crunch?

  We have been seeing a lot of snow this past week in New York. Last week while I was on my way to get some groceries I had a question about why does snow crunch when we step on it. Its always fun playing in the snow and stepping on it and hearing the crunch sound. I did some research on it and read various scholar articles about it. After researching about it, i came up with the answer that snow is made of ice crystals and ice crystals have six points. one snowflake can consist of multiple crystals and there are also gaps between the points of a crystal that are empty, except for air. So, air is trapped inside of that layer of snow when it falls on the ground. After going out and observing myself I noticed that when i stepped on the snow, it got compressed. the air gets pushed out of the snow. The sound that I heard was the sound of the ice crystals as they break. I also did an experiment by breaking an ice cubes. They too make a crunching sound when they are broken. The crunching sound is less related to temperature and more to the structure of the snow. The snow gets more compact as it gets old.
  Kayla Hernandez

  Participant

  February 14, 2021 at 4:30 pm

  Within a park located near my house, there is a basketball court. Inside this basketball court there is a patch of orchids that are growing from the concrete. What is very interesting about this observation is that aside from a few large oak trees there are relatively no flowers within a three-block radius of the park. How did these flowers bloom in the basketball court if there are no flowers surrounding the park? What I did notice is that there are several species of trees within the neighborhood. Additionally, there are some cracks in the concrete where weeds and grass are also spouting from. I believe that the flowers were able to bloom from the concrete despite the lack of flowers in the area because seedlings from these flowers traveled by wind currents from other areas, and then once they got caught in the leaves of tree branches, they fell and landed in cracks within the concrete.

  While it is difficult to test this hypothesis due to the amount of equipment needed, such as track devices and updated information on wind current patterns in the areas, general inferences and basic models should be able to guide us in the testing process. According to the Science Learning Hub, it is said that some flowers have built-in adaptions to aid their seeds in traveling by wind in order to increase their chances of growth. Dandelions, for example, are light in weight while also having bristles for them to be easily carried by the wind. In our case, orchids have balloons and are lightweight, so they could easily travel along with the wind and then deposited on the ground. We tested this by obtaining a fan and scrapping off the seeds from a strawberry before consumption. We placed the fan at 10 miles per hour, and then placed five seeds in front. This was repeated two more times for three trials at 10 miles per hour. On average the seeds traveled a distance of 45 cm. Then the fan speed increased to 15 miles per hour, with five seeds per trial for three trials. After the trials were conducted, the average distance traveled of the seeds at 15 miles per hour winds was 62 cm. Lastly, the fan speed was increased to 20 miles per hour. The three trials were repeated at this speed, with five seeds tested in each trial. On average, the seeds traveled a distance of 78 cm when the wind speed was 20 miles per hour. Based on our model and previous research it is most likely that if the flowers are blooming from the concrete without any flora near the park, then it is wind dispersal that brought the flowers to the park. Although we were limited in the speeds that we could test, it is possible that based on our findings we can amplify our results to reflect the distance seeds traveled from higher wind speeds.

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  Joseph Tatis

  Participant

  February 14, 2021 at 9:40 pm

  Today, I went to shovel my car out of a heap of snow. Since a couple of days had passed since the snowstorm, some of the snow had turned into ice. After using several tools and methods to remove the snow and stuck ice, I could finally sit in the car to start it. I put the key in and gave it my usual crank. To my dismay, the car remained off. With a little stress now part of my morning, I sat there staring at my dash and wondering what could possibly be wrong with the car. “Why does a car not start on a snowy day?”, I asked myself. This question also was specifically for my car. I began to think and decided my best course of action was to try starting the car again. I noticed the dash lights lit up but they were faint. I continued to turn the key, saw the dash lights go out and the car again did not start. I tried one more time but this time turned the key to power the accessories, saw the faint dash lights again and left the key in this position. After waiting several minutes, the dash lights were no longer dimmed and seemed to be normal as the radio even turned on. I attempted to start the car again but sadly, the same issue occurred. It was also a very cold day, around 20F, and I was getting impatient in the driver’s seat. I had observed the issue long enough now had to decide what was wrong. My car doesn’t start on a snowy day because the temperature negatively affects the battery. The battery is relatively new and I’ve restored the majority of the wiring in the car so I knew it wasn’t failing because of an old part. The temperature that day was blistering cold and I was having a hard time keeping warm so I decided the only change since I’ve driven the car last was the temperature. I had actually had a previous experience but with my old phone years ago. The battery could be fully charged but it would die out on me if the temperature outside was low enough, a day like today. After doing some research, I found out that a car battery can lose around 35% of its charge at 32F and 60% at 0F. I concluded that the cold temperature had discharged my battery not allowing the car to start.
  Joseph Tatis

  Participant

  February 14, 2021 at 9:47 pm

  I agree with your observations and the way you went about testing your hypothesis. Another way of testing over a long period of time would be to graph the area of bark shed relative to tree size. This would further support that tree size and the amount of bark shed are linked. I also like how you considered the color of the bark when making your observations.

  Joseph,
  Joseph Tatis

  Participant

  February 14, 2021 at 9:53 pm

  The way you tested your hypothesis with an ice cube was a great way of simplifying the problem in my opinion. Another idea for an experiment would be to see if there is correlation between pressure and temperature. This can be studied with thermodynamics.

  Joseph,

  • This reply was modified 3 years, 8 months ago by Joseph Tatis.
  • This reply was modified 3 years, 8 months ago by Joseph Tatis.
  Kayla Hernandez

  Participant

  February 14, 2021 at 10:03 pm

  This is a really interesting point to make! I never actually thought about why snow crunches and the research that you wrote regarding your hypothesis is really intriguing. I noticed that part of your question was also asking at what temperature does snow begin to crunch under your feet, were you able to find any information regarding that, or what this a dead end? I feel that your experiment could really open up to more pathways, such as testing the minimum pressure needed to create the ‘crunch’ in the snow, and possibly if the amount of snow piled up has any correlated to the amount of pressure needed to recreate the sound. Overall I enjoyed reading your experiment surrounding this topic!
  Kayla Hernandez

  Participant

  February 14, 2021 at 10:58 pm

  Hi David,
  What made you chose tree bark as the topic of your observations? Regardless I thought that your approach to the experiment was really interesting. Based on your experimental design to test the flexibility of tree based off the color and a flexibility test, it seems that your conclusions were valid. I wonder if your experiment came up with inconclusive results then how would you tweak your experiment? Additionally, could it also be possible that the color of the tree bark is an indication of the water consumption of the trees and not solely the expansion and size of the tree? Either way, your observations have formed multiple hypotheses that can be tested.
  Nicolas Mateus

  Participant

  February 14, 2021 at 11:23 pm

  My observation during the winter months was observing how the inanimate objects of Earth are affected by gravity. Things including leaves falling, how fast water drips on the side of a house and the speed of a coin drop, and how it is affected by the acceleration of gravity. My observation initially was that all these things were moving at different speeds since they have

  My question by this observation was how are the inanimate objects of earth affected by the acceleration due to gravity? Is everything that is falling truly affected the same by the earth’s gravitational pull?

  To test this theory I had to move forward with my observation and see if objects of different mass move at the same rate falling from the same height of course. I observed my objects that included things of similar mass and size, which were my chapstick and my wallet’s metal multitool. Dropping them from the same height they hit the floor on par at the same time. My second observation was of objects that were of completely different sizes and mass which were my left shoe and my chapstick. After dropping them I noticed that they also managed to hit the floor at the same time.  My last and final observation included dropping a small napkin holder and my chapstick to the floor and again they also managed to hit the floor at the same time being dropped at the same time. 

  The answer to my question was quite clear regardless of the mass or size of the object the acceleration due to gravity acting on these objects is the same. Therefore objects that are being dropped from the same height at the same time will hit the floor at the same time due to acceleration being constant. This is due to the fact that when we dropped items of the same size and similar mass ( chapstick and metal multitool) and objects that were of different sizes  (chapstick, napkin holder, and shoe) and mass that they all hit the floor at the same time. 

   

  When you have completed these steps, write a paragraph to summarize your \”research\” and post your research to the discussion board. You should use formal language and grammar (no text-message speak), and the paragraph should clearly explain identify: 1) Your research question, 2) your observations 3) your hypothesis, and 4) how you tested your hypothesis, 5) your results and conclusions.

   

  Summarizing statements:

   

  The imposed research question that we sought to test out through our experiment was how are the inanimate objects of earth affected by the acceleration due to gravity? My initial observations upon looking at the events of winter weather looking at how water dripped off the side of a house, how leaves dropped and how fast a coin could drop demonstrated that objects are affected differently by the acceleration due to gravity. I tested my hypothesis, by first setting up an experiment in which different sized and similarly sized objects were dropped from the same height at the same time. In which we used a small napkin holder, chapstick, a wallet metal multitool, and a shoe. The constants in this experiment were the heights that the objects were being dropped from, the moment in which those objects are dropped, and of course the acceleration due to gravity which is always constant. The independent variable that we tested were the different sized objects and the dependent variable being the times which the object hit the floor. We concluded through this experiment after dropping the objects next to each other at the same time and height, that no matter the size and weight of the object, that all the objects if dropped from the same height and time would hit the floor at the exactly same time. Therefore my initial hypothesis was incorrect and it further proves that the acceleration due to gravity is constant on earth.
  Nicolas Mateus

  Participant

  February 14, 2021 at 11:29 pm

  Joseph,

  Your research seems to be unfortunately true, car batteries have a current rating when the battery is cold, this is also known as the cold starting amps that the battery can deliver to the starter to turn over the car. When the temperature is below normal temperatures for the battery, the amount of cold starting amps that the car battery can deliver significantly reduces depending on how cold it is. Sorry to hear about your car, but it is a learning experience and I’m glad you took away useful info from your experience. I do agree with your hypothesis, which is indeed true as I too have experienced this problem with one of my cars that is much older.

  Nick,

   
  Nicolas Mateus

  Participant

  February 14, 2021 at 11:37 pm

  Saundarya,

  I never took notice of how snow crunched, it is interesting that you mention that what we’re hearing is a combination of the crystals breaking and the air getting pushed out of the snow we are also stepping on. Would this also explain the sounds we hear as were sledding down a mountain or maybe the sounds we are hearing when ice skaters are creating with their skates? The assimilation to the ice cubes bring about this question and also answer why when we step into the footsteps of other people in the snow we hear it less than if we were to step into snow that hasn’t been stepped into. I agree with your hypothesis, as it explains many phenomenons occurring in the world every day and hardly notice.

  Nick,

   

   
  Saundarya Sharma

  Participant

  February 14, 2021 at 11:53 pm

  Byungjun Shim,

  Your experiment and the conclusion you provided was very insightful. The way you conducted the experiment with the ice cube was very interesting. You concluded you experiment saying  it was the pressure that melted the ice instead of the heat which then made the ice slippery. Have you come across new research articles that stated hat ice’s slipperiness may be due to “extra” molecules on the surface of the ice? I feel these new research articles would be interesting for you.