Two weeks of FUN

     Hey everybody, I'm back. I know I didn't post a blog last week, but I wanted to try something new, instead of writing a blog every week and have some topics run into the next week, I wanted to try and blog after a new concept is completed, also, writing a 4 page blog takes up a ton of time, which I wanted to myself for once. Anyways, the last two weeks we have been continuing our focus with motion maps, mathematical equations, and a bunch of other graphs that show velocity, position, and time. These are all good and well, but the main things that caught my eye was the explanation of average velocity, average speed, displacement, and interpretation of some graphs. This is because I have sooooo many issues with these concepts (or at least I used to).
     To begin with, on the first day of the first week we had a long discussion on what is displacement. You see, our leading theory the week before was how far an object moved between two points in a given amount of time. However, this theory thrown out the window as soon as we started class. It turns out one of my classmates had a different view of what it was and moved right to that theory. The person's theory stated that displacement is no more than how far an object moves in relationship to the starting point, which did make a little sense, especially, when put into context with the packet we had earlier. The packet defined displacement as "final position minus the starting position". Even though we came to the right answer I was a little angry. This is because not only did we skip over a viable theory (the one I had long supported also) and despite 30 minutes of raising my hand, we never took a second look at that theory. It wasn't until after 45 minutes that my quest was completed and I had closure. Also, I wasn't the only kid who had a problem with not being called on, I know of at least 2 other kids who could not have their voice's heard. It did however, get better. This is because Mr. B. intervened on our behalf a couple of times. I think the plus- delta we had is doing wonders.
     After that, there was the average speed and average velocity equations I could not remember to save my soul and when I read them it was like reading gibberish. The actual equations were written as " average velocity is the displacement (final position minus original position) divided by the time elapsed" and average speed was " the distance traveled along the path (change in odometer reading) divided by the time elapsed". The only thing I could get out of those definitions was the fact that the denominator was how much time went by. It wasn't until we had two packets that I finally understood what to do. It turns out with average velocity you just divide displacement by the time elapsed. This was easier for me to remember, but there was another way of solving average velocity also. It involved connecting the two points directly and finding the slope. That was my initial guess as to how to do this equation, but I was not sure. As for average speed, it involved counting up all of the distances period, and then divide it by the amount of time that had passed. There was one other caveat though, there is no such thing as a negative speed so if we had a negative speed we would use the absolute value. These two conversations took up the entire time in the first week.
     In the next week we talked about interpreting position vs. time graphs, motion maps, and velocity vs. time graphs. This was done in the form of another packet (which I forgot we had). Even though I forgot to do that packet I was able to have my voice heard, this was also due to the fact that we implemented the hand raising system for talking.
    The first thing we talked about was the position vs. time graph. This started out with us drawing the graph to replicate the movement of a skater. Now, all of the class drew a standard graph with sharp curves and straight lines because we assumed that was how the skater skated based on the data. However, Mr. B. pointed us in the direction of other possibilities, like curved lines instead of straight ones, also a gradually decreasing speed when the skater stop not a sudden drop. This led to a lot of confusion, especially when we tried to translate all of the possibilities. For instance, when we had a curved line between the points we said that the skater was gaining speed and for the sharp drops the skater tripped and fell, but in the end our original design was correct.
    After that side note we started to talk about the infamous motion maps. Now, I say infamous because all of us hate these maps because almost no one really understands them. Some of the things that we talked about this time pertained to one map in particular, it is is shown on the right.
The question was how many seconds can we actually count. Half of the class said 3 seconds and the other half said 4. The argument for 3 seconds was the fact that there were only 3 complete cycles of a dot followed by an
arrow ending with another dot. Then, the argument for being able to tell 4 seconds was the fact that it is the arrow that tell the object's speed and duration of travel, therefore, since we had the arrow and it was a constant length we could assume the next point would follow the same pattern as previously produced. I supported that theory until the bitter end, it turns out we could tell only three seconds because the speed or duration of the skater could have changed with in the data down the road. This discussion did however, bring spark
my question of "if we can't assume the point of the next cycle then what do we do with that line?" This question was not answered this week, but Mr. B. heard it and really liked it, so it will be asked next time. Some other questions that I would like to ask include "what do each part of the motion map represent, like the arrow or line" or "why don't we use lines or segments instead of rays". My guesses for these questions in order are, 1. it doesn't represent anything, 2. the arrow represents the graph continuing and the line is how fast  the object is moving, and 3. we use a ray in order to represent the starting and ending of a period.
    After that, we talked about whether each point represents a second or just a snap shot of time, along with what can do with that information. We did this by using the moving model again. Mr. B walked along a marked path dropping bean bags at even intervals of time to represent the points of the map. This showed that each point does represent a snap shot in time. That was my original guess, too. Next, was the realization that on any type of graph speed or velocity cannot be found without 2 or more points. This went back to the comment of the slope being the speed of the an object.This was more of a statement by Mr. B than anything.
     After that, we discussed what the area in between the axis and line meant on a velocity vs. time graph. We first had to find out what each box meant, and that wasn't hard. We just had to do a little cross multiplying and we were done. Each box (for our graphs) represented one meter. We did however, learn something to be aware of, it was to make sure that we actually multiplied and not set up my equations as if we were dividing. From there, we counted the number of boxes between those two lines and that apparently represented the displacement of the object too.
     Next, we briefly touched on relations again, specifically on whether we should name a velocity vs. time graph with a horizontal line as "no relationship". This issue was again a split right down the middle of the class. Some were saying that there was no relationship based on our previous discussions from week 1 and 2. However, the actual question was to write the mathematical equation that represents that set up. Then, the other half of the class remembered that for a horizontal equation it is just y= a number. We resolved the issue by just putting both forms and say that it's a matter of preference.

     Finally, we talked about how all of these graphs are interconnected. We talked about how we could take any of the representations of movement we learned i.e. the position vs. time graph, velocity vs. time graph, motion map, description of the event, or a motion map and make all of the others. In fact, that is what our homework is on, we have to create the other 4 representations for the one representation that is given to us. Later in the future Mr. B. said we will be getting into some of the laws pertaining to motion, so that will be fun.
    
Here are some helpful sources if there is still any confusion on any of the topics I discussed
http://www.physicsclassroom.com/class/1dkin/u1l4e.cfm
http://www.physicsclassroom.com/class/1dkin/u1l1d.cfm
https://www.youtube.com/watch?v=gC0hlJlbu1A

Velocity Graphs, Motion Maps, and Postition Graphs: Ohh My

      This week we finished the lab that we started last week. I know I briefly explained what we had to do and we ran into some issues, but here is a recap. The lab we had to do was just recreate some position vs. time graphs and record what the velocity vs. time graph was that correlated with the former. This process was also flipped for part of the experiment. Some issues we ran into included the fact that at first our motion sensor wouldn't register our movement. It was, however, a very simple mistake that we made. We had the sensor motioned above us, so instead of it being paraell to us it went straight over our heads.
      After that little hick-up was fixed we started working. Initally, I was on top of everything. I the speed at which an object is moving in relationship to a reference point. If the distance gets smaller then there is no increase in distance from the reference point and is therefore negative. understood the graphs that we had to make, what they meant, and how each graph correlated with eachother. However, that is until we came to a graph that was coming twords y axis and not away from it. I had the right line (a simple horizontal line), but I misplaced it in relationship to the axis. Instead of it being above the axis it was now below it. That was my first mistake. I did quickly learn from that mistake and it does make sense. This is bcause velocity is no more than
      Then  everything continued to  move along just fine, until we came to another graph, where my graph turned out to be wrong. In this graph the line went in a positively linear fashion, then went in a horizontal line across the graph, and finally came down in a linear fashion. My guess was that the velocity graph would first go straight across the gaph above the horizontal axis, then go even with the axis, and finally dip down below the axis. My thinking was that there should have been no transition between speeds, because the changes were simetaniously, however, this theory was challenged by one of my groups members. She said that there would be a slight trasition between speeds. I will admit that I was very stubborn and would not give into that theory. In factm it took four different sets of data to finally convince me.  In the end though, I did agree with her.
      Next, there was the rest of the graphs. They again went extremely smooth, and I understood the concepts just fine. Although, that's were I ran into another problem this time with my goals from last week. Once I understood the consepts I start to dominate the lab, and that's a problem, but, instead of just giving the answers away, I asked a lot of questions that I thought would lead them to the answer. This seemed to aggravate some of my group members though, and I can't blame them. After all, when our teacher does that to us I hate it.
       After that, a rarity happened. We actually had homework. It was again extremely simple and was based on the lab that was done that day. The only expetion were three questions at the bottom, and the only confusing one was number three. It asked what "what does the area below a time vs. a velocity graph tell you about the motion of an object". The funny part was that none of us at my table had gotten that question either, so Mr. B had to actually explain it to us. It turned out to be very simple. The answer was "how much distance an object travels in a set amount of time". The way Mr. B. showed us was with one of our standards, naming the units of a graph, along with a simple problem of dimesnsional analysis.
     On the next day there was a plus delta on the whole class, and the main points I was thinking were brought up. A couple of pluses that was brought up was the fact that Mr. B is extremely nice and does care about our learning. We also like how he lets us learn from our mistakes and lets us redo tests accordingly. Then, some of the deltas was the fact that Mr. B. never gives us any conformation/negation to our findings. We dilike how he doesn't really give us any type of guidance in the conversation. That leads us into a circle and we never have a set answer to the question. He says that the reason he doesn't really give us too much guidance is because when he isn't at school he wants us to carry on class as usual. He also says that most of our classes will be run by the kids and that we will have to come to the realizations not have the teachers say too much, therefore we better learn now. Finally, some of the toss ups included the fact that he gives us room to learn, isn't a dictator, and these blogs. These we toss ups because there are good things to them and bad. For instance, its good that he doesn't control our every move but bad because we can't focus, and the blogs organize our thoughts but they are so time consuming, and there was a huge negative feeling to the blog buddies too.

 

     After the plus/ delta, there was the discussion on the lab itself. Here we talked mainly about motion maps. This was particulary helpful to me because I did not understand how to do a motion map to begin with. It turns out they are just a bunch of arrows going in a direction to represent where an object is going in relationship to a reference point. It also shows the speed the object is at. For instance, short arrows means a slow speed and a long arrow means fast. After that, we learned that dots meant that there is no movement at all. Finally, we got to what each line means. For instance, a velocity graph with a negative horizontal line means  that the object is moving twords the reference point, a positive horizontal line means that the object is moving away from the object, a straight line going along the x axis means that there is no movement. A current theory I have is that a smooth curve line would have a gradually building speed. That would be something else to consider testing also. The one thing I do want to change though, is the fact that in these discussions there are really only three people talking (and no it is not me). Mr. B. has heard this issue before and addressed us about it. We even went as far to say that those three people couldn't really talk, but it still happen. Also, there were still kids getting cut off in their questions, I even had to speak up for one of them. I also never got the cahnce to ask my question of "why do we use rays in motion maps and not something else". I know I did talk to Mr. B about this and suggested that part of the problem is that most kids weren't comforatable just shouting out things and sit quietly/raise hands. Therefore, by actually calling on kids with hands raised would help that problem tremendously.However, therewas a partial plus to all this madness. With having the three kids tone it down a little we did hear from other people more so.

 

Everything put together

The Endless Worksheet

This week was a relatively slow week again. This time we did three things. The first (and longest) thing was go over our homework, which was very easy to do, however, the conversation that came from it, not so much. The conversation focused on explaining two graphs and each meant. For instance, do the two cyclist start at the same point, who is traveling faster, are their velocities the same ever, and what is happening at 5 seconds (no, cyclist A, no, they are at the same position). These questions were again easy to answer because most the we just had to look at the graph. However, some discrepancies came into play on the first graph. For instance, is velocity and speed the same thing? This question stumped most of us, and even at the end of the day we never really came to a conclusion. This is because speed=distance/time and we thought so did velocity. Then, the argument for them not being the same was the fact that velocity has a set direction. That was then compared to speed and how it is connected to position, which, as mentioned before has many dimensions. This theory isn't necessarily the most accurate, though. This is because according to some additional research  velocity is constantly being compared to is position from the starting point and speed is merely how fast an object moves. It is sort of like mass and weight, while on the streets everyone uses them interchangably they are completely different. Here is an article to further explain the difference between velocity and speed...  http://www.physicsclassroom.com/class/1dkin/u1l1d.cfm

After that little snafu, there was another discussion on whether slope actually meant speed/velocity (the slash is because we still weren't sure which one applied here). Most of us thought that yes it was directly related to speed, however, that theory was tested when we noticed on the second graph that it had a negative slope. We thought this because the graph showed change in distance/ change in time which is the equation for speed. The negative slope was confusing but manageable because of the discussion from last week. This is because we assumed that the reference point from which the bicyclists started from was fixed and therefore each bicyclists was traveling in opposite directions in order for bicyclist A to loose distance. That led to the conclusion that the speed is just the absolute value of the slope. That is because even though bicyclist A lost distance is had to loose distance at some rate (i.e. speed).

After a whole day spent on checking the worksheet came the discussion on our blogs. Now, this doesn't really have much to do with physics so here was our conclusions in a nut shell. We will have to read two peoples blog every week, comment on them using the acronym NICE (new ideas, improvements, complement, and explanation), and we will rotate every month- progress report. This whole idea was to see other people's point-of-view and to improve our own blogs. I do believe that this will help us tremendously, as it is I hope the people who have been reading these blogs consistently will see some differences as the year progresses.

Finally, we ended the week with trying to do a lab. Now, this lab wasn't a traditional one, we never really got to finish and we had to try and use a motion sensor to recreate these graphs. This was inspired by the worksheet from Monday. Now, there were some very difficult points for my group, because not only were we missing a person but we also couldn't get the sensor to work. We connected it the computer the right way but no matter what we couldn't get a reading off of it. We tried a total of 5 times and only one test produced actual results. Also, the results we got weren't what we expected. I just hope that Wednesday will be better...

On another note here are some things I want to try to do. To begin with I need to try to stop explaining things and learn to be quiet more so, especially when it comes to predictions. This is something that my teachers have been stressing and it is extremely difficult, especially in science. I know to most people in my class notice I rarely talk, but in smaller groups I talk way too much. I also need to work on listening to other people's ideas more so. I currently listen to the people but not as intently as I should. Finally, I need to try and make blog more interesting/ fresh. I hope I will get some ideas from some of the other blogs I will be reading.