Tuesday, August 30, 2011

My Acceleration Lab

       Today in science Diana, Sinai, and I tested with accelerometers. Acceleration is the rate at which velocity changes. The accelerometers were used to measure the acceleration of certain objects which would then be graphed using Logger Pro. 
Here's what all of our tests looked like on a graph:
Since that graph is confusing, I will separate the tests so you can see the graphs individually.



For the 1st test, Diana sprinted 25 meters with the accelerometer. This is what her motion looked like:
As you can tell by the graph above, Diana's sprinting was pretty consistent peaks. There was generally the same amount of space between each peak, and she accelerated a lot when she first took off.


       For the 2nd test, I sprinted 25 meters. This is what the results looked like:
       The spikes in my test were more close together than Diana's and they were slightly larger. They strayed from the middle line of 0 more than Diana's graph did. I also had a bigger starting spike than she did, so I accelerated faster than her in the beginning.


For test three, Sinai sprinted 25 meters. Here are his results:
       Sinai had the smallest spikes in the beginning. However, he had large spikes for the most part, until the end when he decelerated.


In tests 4-6 my group and I had to hop 15 meters. I was the first to go and these were my results:
       As you can see, the spikes are more spread apart than they were in the sprinting tests. This is because when you hop, you travel and then stop, travel and then stop so Also, on the force graph, The lines were generally in the negatives whereas in the sprinting graphs, they were in both.


       For test 5, Diana hopped 15 meters. These are her graphed results:
      Diana's graph looks similar to mine because we both had consistent peaks in acceleration. However, in her force graph, she had more peaks in the positive section then I did, meaning that her hops were faster.


       In the 7th test, Sinai hopped 15 meters. Here are his results:
       Sinai's results are the most unique. However, they are slightly skewed. This is because when the graph has the lower peaks, (towards the middle), it shows when Sinai tripped. Had he not tripped, his results would have been more consistent like mine and Diana's were.


       Tests 7-9 were open tests where we could basically try whatever we wanted to. For test 7, Diana skipped for a distance of 25 meters. Here is what it looked like:
       Her peaks were the most spread apart of any previous test. This is most likely due to the fact that when you skip, you jump up and move forward, then switch legs, and jump and move forward again. The peaks would be the acceleration from the jumping action.


       For test 8, I did one-handed cartwheels for a distance of 15 meters. This is what it looked like when graphed on an acceleration graph:
       I think these results are inconclusive because the accelerometer went upside when I did. The repeated motion of cartwheels makes the acceleration fairly consistent. I believe it changes near the end because I started going sideways when I did the last few cartwheels.


       For the final test, test 9, Sinai just spun around with the accelerometer in his hands. This is what the graph showed:
       Sinai's acceleration was more more positive, his force was more negative. I think that is because he got faster as he spun longer, that is until the end when he stopped himself.


       Overall, this was a great experience that taught me about how acceleration can be measured, and how to use an accelerometer. 

Wednesday, August 24, 2011

Motion Lab


        For this lab we used a motion sensor. We did a number of procedures which required us to walk forwards and backwards in front of the motion sensor. 


For the 1st test we walked away from the motion sensor to a distance of 1 meter. I predicted that the graph would show a negative slope (velocity) but this is what actually happened:
As you can see, my prediction was incorrect because a positive velocity was graphed.

        Next my group tried matching a graph. This is how close we got:
To get this result we had to wait, then walk backwards, then wait again to show that there was a 0 slope followed by a positive slope.

        The differences between those two graphs are that the 2nd graph has a change in velocity, whereas the 1st graph has more of a continual slope. 

       Next I predicted that if you walked towards the motion sensor, the slope would be negative. The test supported my prediction.

        When my group and I started from farther away from the motion sensor and walked backwards faster, the slope was more constant with a few peaks and dips here and there. As shown in the graph below. 

        For the next test we had to match a graph. This is the best my group could do:

        The difference between those two graphs is that the 1st one was more constant and the 2nd was was impossible for us to match. We found it hard because Graph 2 had a steady velocity, then it spiked up, and then it stopped again. To get as close as we did, we had to wait, then walk, and then wait again, but it still wasn't anything near the original. The lines are different because the 1st graph had a less dramatic spike in velocity and the 2nd graph was all over the place.

        Velocity is a vector quantity tat refers to "the rate at which an object changes it's position."

        The acceleration vs. time graph differs from other graphs because it measures the rate of change in acceleration. Acceleration is the rate at which an object changes it's velocity. Here is an example of an acceleration vs. time graph in comparison to the other graphs: 

        In conclusion, this lab taught me different ways to graph motion and the physics of simply walking forwards or backwards.

Monday, August 22, 2011

Moving Man

Today I used the "Moving Man" simulator to demonstrate how position, time, velocity, and acceleration relate to each other. 

     I found that when I used a higher velocity, the man walked faster to a positive position (he walked forwards toward the house). The graph below represents this and it has a positive slope. 



     Also, I found that when there was 0 velocity, and 2 acceleration, the graph showed a curve. And the man moved fast in one direction until he stopped.


     Then I tried a negative velocity and the graph turned out like this. This shows a negative slope, meaning that the Moving Man walked towards the negative numbers.


     From the many different combinations I tried, I concluded that the higher the velocity (slope) and acceleration, the faster the object will go. Also, as time passes, the distance of the object will increase/decrease too, depending on the velocity and acceleration of the object.

Thursday, August 18, 2011

Women's Brains Bias

WOMEN'S BRAINS Bias
by Stephen J. Gould in "The Panda's Thumb" 1980 (pp 152-159)
DISCUSSION QUESTIONS
  1. What is the general point that Gould is presenting? 
Gould is presenting the point that all of this data is irrelevant, inconclusive, and bias. It doesn’t matter if you are woman or man, big-brained or not, white or black. It doesn’t mean you are smarter than the next person
  1. What is the general evidence on which that conclusion is based? 
Gould uses different scientists’ data to show ALL the facts and he exploits the faults in them. He shows both sides of the argument however, he does come back and make the reader believe his points.
  1. What is the gender of all the researchers producing those data and conclusions? 
Most of the scientist who think males are smarter than females are males themselves. They are being gender bias.
  1. What weaknesses or problems with those data and their interpretation does Gould point out? 
Gould talks about the experiment performed by Broca and finds that the brains of the females that Broca examined were significantly older than those of the male brians he examined. Older brains weigh less than younger ones, so this is a weakness in Broca’s data.
  1. a) Name the one woman anthropologist mentioned who studied the subject of this essay. 
Maria Montessori.
  1. What did she find after proper correction of Broca's data? 
She found that women had slightly larger brains than men.
c) What were her conclusions from that finding?
She concluded that women were intellectually superior, but men had more hierarchy because of physical force.
  1. What conclusion does Gould reach about the central issue?
Gould believes that biological value upon groups is heinous. He says himself “I would apply it (classification of smarts) more widely—not only to those whose dreams are flouted but also to those who never realize that they may dream...” This opens a new door to comparing by disadvantaged groups to advantaged groups and seeing who is more intelligent.
  1. Make a general statement about the role of bias and assumptions in the collecting, processing, and interpretation of data in scientific studies.
Everyone has a background which unfortunately sets our brains into thinking some sort of bias towards something. Everyone is bias towards something and everyone interprets things differently. How we share our data is also unfortunate because most scientist shed more light on the data in their favor rather than the data they don’t want.
8. What other kinds of bias can you think of that might influence observations and interpretations in science?
I think if people are bias towards vanity than it could be a HUGE problem. For example, if someone was doing an experiment too see if brunettes were smarter, and they were a brunette themselves, their conclusions could be very biased. The same goes for blonde, blue eyed, big-eared, etc. people.
  1. Describe your initial feelings (about the subject, the author, etc.) after reading the first 4 pages.
I thought it was completely false information and I was outraged at the views of the biased scientists.
  1. Describe your feeling after finishing the entire article.
I felt content with what Gould’s view was, it was certainly much more fair then the other scientists.