Lab 2: Scientific Method

• 

  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.

• Rose Crisostomo Cabrera

  Participant

  February 8, 2021 at 6:22 pm

  Why does my coffee get cold over time/ why does my coffee not stay hot? After I prepare my coffee and pour it into my mug, it becomes cold over time. It does not get super cold (for example, it does not freeze) but it significantly cools down relative to when I first brew it in the coffee maker. Hypothesis: If the temperature in the air is different than that of the coffee, then the coffee’s temperature will change accordingly to balance out. “Tests”: Putting coffee in a freezer: the coffee will then adjust and get significantly cooler. Putting coffee in a very hot weather environment: the coffee will then remain hot or get even hotter (depending on the temperature). My results show that the temperature of coffee in a mug is directly related to the temperature that prevails in the air. In math, we use Newton’s law of cooling in Ordinary differential equations to model out how this works. “The rate of heat loss of a body is directly proportional to the difference in the temperatures between the body and its surroundings. ” Source: https://en.wikipedia.org/wiki/Newton%27s_law_of_cooling

  • This reply was modified 3 years, 9 months ago by Rose Crisostomo Cabrera.
  • This reply was modified 3 years, 9 months ago by Rose Crisostomo Cabrera.

  Attachments:

  You must be logged in to view attached files.
  Kevin Cardenas

  Participant

  February 8, 2021 at 6:44 pm

  Can snow in the sun cause other snow to melt faster? I found that snow has a reflective property because of its white color, and so it does not absorb heat as fast as a darker material. Snow that is in the sun melts faster than snow that is in the shade. When snow is angled in a way so that it reflects sunlight onto other snow, the snow receiving the reflection will melt faster due to two sources of sunlight placed on them. I would test my hypothesis by setting up different simulations of environments where snow is positioned in different ways. One of these would be snow in a flat layer. A second one will be a flat layer of snow next to a hill of snow. A third one will be two hills of snow next to each other. Due to the reflectivity of snow, when more sunlight is incident on any snow there is more heat to be absorbed and so it will inevitably melt faster.
  Rose Crisostomo Cabrera

  Participant

  February 8, 2021 at 6:50 pm

  Why does the air feel sticky/’wet’-like after it rains? After it rains it becomes very humid. The air feels stickier and heavier than normal – and gives a wet feeling to the skin. This is in contrast to when it does not rain. Another observation is that it is not the rain itself that gives the air this sticky wet feeling, rather it is something about the air that is different. 3) If it rains, then humidity rises due to water evaporating causing the air to feel “sticky”. 4) After doing some further research, I found that there is a common test you can try to determine the relative humidity inside your home. The first step is to place two or three ice cubes into a glass, add water and stir. Wait three to four minutes. If moisture does not form on the outside of the glass, the air is too dry. I tested this outside in a day where it did not rain versus a day where it did rain (after the rain had stopped) and the moisture formed outside of the glass on Rain Day was significantly more than the No Rain Day; this showed that the air had higher levels of humidity due to water evaporation earlier in the day. My conclusion is that my hypothesis was true and this was shown via the experiment: The air feels sticky after it rains due to water evaporation after rain causing moisture which leads to humidity.

  Attachments:

  You must be logged in to view attached files.
  Rajwinder Singh

  Participant

  February 12, 2021 at 6:58 pm

  Why  has the Statue of Liberty changed color over time? Originally this symbol of our country was gifted to us by the French in 1885 as a gigantic statue made of thirty tons  of copper, which is of course a brownish/reddish color. At first, I wondered if this had anything to do with industrialization of New York City, as it inevitably would lead to polluted air. On the other hand, it could be the drastic changes of weather the city faces annually, as any New Yorker would know, we live through 12 seasons each year. Back in highschool, where I took a sheet metal class, I learned of various types of corrosion and deterioration of metals.  One chemical process that can cause changes in the composition of a metal is oxidation, where oxygen steals an electron from elements such as copper. If copper metal is oxidized, then the copper will change in color. With 21% of the air being oxygen, along with the other chemicals in the air of New York City, it would make sense that the statue’s copper went through a series of reactions to form the green/teal color we see today. These reactions produce different minerals, hence creating multiple color changes to the statue over time. For example, oxygen reacts with copper, producing a pink cuprite mineral, which reacts to oxygen to produce a dark tenorite. Finally as I inferred before, as the use of automobiles and technology has increased, the production of sulfur dioxide has polluted the air. This reacts with the water surrounding the liberty island, creating sulfuric acid that reacts with the tenorite. This eventually developed the mineral that covers the statue today, atacamite. Back in the sheet metal class, I had already tested this research, by oxidizing a penny to see if I would see the same green color as of the statue. I added nitric acid to a penny in a bowl, which immediately started oozing a greenish color, which were the copper ions. Eventually after waiting until the next day, most of the penny was green. In conclusion, this leads me to say that my hypothesis was true that oxidation and the presence of a polluted city atmosphere led to the color change of the statue of liberty.

  
  Luis Antonio Alchundia Laborde

  Participant

  February 13, 2021 at 3:37 pm

  Back to 2017, the year when I decided to move into the US, I realized on my first winter that people used to spread salt all over the floors before any snowfall to prevent slippery roads, sidewalks, etc. Three years later, Eventhough I know the purpose and efectiveness of salt spread on this type of situations, I did not know how the salt act in combination with the snow, chemically speaking. So, for that reason three questions have come to my mind now:

  1. Why salt is the first choice for people on this type of situations?
  2. How the composition of NaCl act in touch with snow?
  3. Is there any other material besides NaCl that can prevent slippery floors on snow days?

  Obviously, this would be very hard to understand and explain if we do not have any chemistry basis. On the other hand, it would be very easy to check on google the answer and not going over the process of thinking, but I’m taking this opportunity to share my though about this  just to know if other people think the same before. My believe is that maybe we can relate the salt crystals and the snow (water) with some process of absortion, preventing the cold weather to freeze that water over the soil.

  Attachments:

  You must be logged in to view attached files.
  Diego Silva

  Participant

  February 14, 2021 at 8:23 pm

  How can clouds float if they’re full of water? Clouds are always portrayed in tv as some fluffy and light pillows you could just lay down, but in reality we all know you cant even touch them to begin with. However, something not a lot of people might know is that the average cloud can weigh over a million pounds. Over the last few days I’ve been looking at clouds and notice that most of them still look huge when they’re so far away. Also thinking about how things float I recalled how things with different densities rise up or fall down. Using this information I feel confident about answering my initial question. Clouds are able to float because they’re made out of tiny water droplets that are formed from warm air that rises up. Warm air is less dense than cold air, therefore it rises up and it then converts into tiny water droplets that combined with others form a cloud. I tested my hypothesis by shaking a dusty rug. the dust particles can float around before falling because they’re so small and have almost no weight. Based on these results my hypothesis is correct and i succesfully answered my question.

  Attachments:

  You must be logged in to view attached files.
  Diego Silva

  Participant

  February 14, 2021 at 8:27 pm

  I agree with your hypothesis and conclussion, especially becasue I’ve seen pennies turn green over time as well. You did a good job and the picture fits in perfectly
  Diego Silva

  Participant

  February 14, 2021 at 8:30 pm

  I had never thought about this topic, it’s really interesting and I agree with your conclussion. The way you would test your hypothesis is clear and a good way to get accurate results. Overall I think you did a great job, but having a picture might’ve helped too.
  Rose Crisostomo Cabrera

  Participant

  February 14, 2021 at 10:53 pm

  I really like this lab-thought experiment. Something I took away from this were the questions you posed – I think that it allowed you to form a solid hypothesis.
  Rose Crisostomo Cabrera

  Participant

  February 14, 2021 at 10:53 pm

  I cannot delete this. Please see other post below.
  Rose Crisostomo Cabrera

  Participant

  February 14, 2021 at 10:55 pm

  I like the way you came up with the experiment to test your hypothesis — it is relatable and demonstrates the concept clearly.
  Jaemin An

  Participant

  February 14, 2021 at 11:53 pm

  Why do strawberries spoil so fast?

  Every time I buy, wash, and store strawberries, I realized that strawberries tend to mold and spoil after a few days. Even though I knew that strawberries are more prone to spoilage, I did not know how to increase the shelf-life of strawberries. I did not know the answer to the following questions about my observation:

  1. Why do strawberries have short shelf-life?

  2. How does the composition of the strawberries affect its shelf-life?

  3. Are there any methods to increase shelf-life of strawberries?

  Strawberries contain spores which can absorb and soak water leading to spoilage. Washing the strawberries few days prior to eating them or leaving them soaked in the water for a long time can lead to strawberries becoming slimy and moldy. I think one way to increase the shelf-life of strawberries and prevent them from spoiling quickly is to use vinegar in addition to water when washing the strawberries. After experimenting with different materials commonly found in the kitchen such as salt, baking soda, and vinegar, I feel confident that vinegar is the best material to use to increase the shelf-life of strawberries as well as retain the original flavor. Salt water and baking soda increased the shelf-life of strawberries slightly by 2 days whereas vinegar increased shelf life by 3 days. I mixed ½ cup of vinegar and 1½ cup of water into a large bowl and washed the strawberries using the mixture for a few minutes. The vinegar helped disinfect the strawberries by removing mold spores which were main causers of strawberries’ quick spoilage. As I have observed, vinegar helped keep the strawberries fresh longer than the other materials used.

  • This reply was modified 3 years, 8 months ago by Jaemin An.
  • This reply was modified 3 years, 8 months ago by Jaemin An.

  Attachments:

  You must be logged in to view attached files.
  Rajwinder Singh

  Participant

  February 15, 2021 at 2:45 pm

  I agree with your concept about light reflecting snow to make it melt faster because their many sources of light including the sun and those of the snow around them
  Rajwinder Singh

  Participant

  February 15, 2021 at 2:49 pm

  You had a really well developed theory, and you used a relatively easy way of testing evaporation in a cup full of ice cubes during a rainy day and a non rainy day. I agree its not the rain itself, but the rain acts as a catalyst for the air to collect moisture and create humidity.