question form

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Phy 122

Your 'question form' report has been received. Scroll down through the document to see any comments I might have inserted, and my final comment at the end.

** Question Form_labelMessages **

Measuring Atmospheric pressure

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I have a question concerning a portion of the Measuring Atmospheric Pressure Lab Part 1

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At the point where we are about to collect data the instructions say Indicate on the first line the vertical position of the first mark on the vertical tube, relative to the water surface, giving a single number in the first line.

On the second line give the length of the air column, as measured in units of the device you used to measure it.

On the third line, give the position of the meniscus before the first squeeze then the position of the meniscus when the water in the vertical tube was at the first mark. Give this information as two numbers, delimited by commas.

Are we measuring the water column in the vertical tube and the air column in the pressure tube here? Would the first line be related to the vertical tube while the second line is related to the pressure tube which is relatively horizontal?

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Thanks for your help.

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The meniscus being measured is in the pressure tube.

Each measurement will consists of recording the position of the meniscus before squeezing the bottle, then squeezing the bottle to raise the water level to the appropriate mark (which will simultaneously compress the air column in the pressure tube), and once more measuring the position of the meniscus (which will have moved as the air column was compressed).

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Thanks for submitting this question. I've slightly expanded the wording in the document for this experiment to be sure it is clear that the meniscus being referred to is the one in the pressure tube.

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question form

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Phy 122

Your 'question form' report has been received. Scroll down through the document to see any comments I might have inserted, and my final comment at the end.

** Question Form_labelMessages **

Kinetic Model

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The first part of the Kinetic Model Lab instructs me to send you an email answering some questions. I sent one last week and I am following up with the same info in this format.

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I don't think my program (the one designed for Windows) is set up the same way as the model the lab discusses. The simulation seems to run properly, but as you can see from my answers below I don't seem to be in synch with the lab directions.

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Watch the KEx and KEy values as they change with each collision, representing the total x and y kinetic energies of the particles.

Watch the 'red' particle for a couple of minutes, estimating the average time between its collisions and its average speed (one of the speeds given near the top of the screen corresponds to that of the 'red' particle--which is it?).

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I am running the Windows version - Billards. There is only one speed given in the program and it does not seem at all to reflect the changing speed of the red ball. Also, there are 2 red balls at the start and one gets erased

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Watch the 'blue' particle, and speculate on what property of this particle is different from that of the other particles.

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The Windows settings were different from the one's you laid out in your description so I tried to mimic what you laid out above in terms of number of balls and relative masses. The blue ball seems to move more slowly - which would be expected because it is more massive.

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Watch as the 'red' particle sometimes turns yellow. What causes this? What property does the particle have when it is yellow?

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The red particle has not turned yellow.

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What might the graphs represented at the right of the screen represent?

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There are no graphs at the right of the screen

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Thanks for your help

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The instructions were still posted based on the DOS simulation. I've revised the instructions accordingly.

I apologize for the oversight and the confusion.

No need to resubmit the preliminary observations, but do take a few minutes to run through the revised instructions for that part.

Then as followup do the selected experiments

kinmodel_01

and

kinmodel_03.

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