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Phy 121
Your 'cq_1_02.1' report has been received. Scroll down through the document to see any comments I might have inserted, and my final comment at the end.
** CQ_1_02.1_labelMessages.txt **
The problem:
A ball starts with velocity 4 cm/sec and ends with a velocity of 10 cm/sec.
What is your best guess about the ball's average velocity?
answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):
My best guess for the average velocity of the ball is 7 cm/sec
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Without further information, why is this just a guess?
answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):
We only know the intitial and ending velocities. We do not have enough information to get an accurate answer for what happened in between the two points so we have to guess or give a good guesstimate.
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If it takes 3 seconds to get from the first velocity to the second, then what is your best guess about how far it traveled during that time?
answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):
I believe the amount that it traveled was around 9 cm.
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The ball never travels at less than 4 cm/sec, so in 3 seconds it would travel at least 12 cm. So 9 cm is not a reasonable answer.
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You should also have briefly indicated how you got this answer. Had you done so I would have been able to tell you a little more.
However I believe you'll get this pretty easily when you do the revision.
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At what average rate did its velocity change with respect to clock time during this interval?
answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):
6 cm / 3 sec = 3 cm / sec
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I think you're making the right calculation but just missing some of the units. However you haven't included any explanation of how you got the result, so I can't tell for sure.
Ideally you would briefly explain how you get from the definition of average rate to your result, which would take a few steps.
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*#&!*#&!
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You had two errors, one of which I suspect was pretty minor; I predict you'll easily correct the other with just a little thought. However both need to be revised.
&#Please see my notes and submit a copy of this document with revisions, comments and/or questions, and mark your insertions with &&&& (please mark each insertion at the beginning and at the end).
Be sure to include the entire document, including my notes. &#
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Finally, suppose that the temperatures given above occur at clock times 10, 20, 30 and 40 minutes. Report temperature vs. clock time in comma-delimited format, one temperature and one clock time to a line.
Then in a fifth line, report in comma-delimited format the average rate of temperature change with respect to clock time, in degrees Celsius per minute, on each of the three intervals.
Starting at the sixth line state what is reported in your lines, and how you obtained your average rates.
your brief discussion/description/explanation:
27, 10
17, 20
12, 30
8, 40
16, 25 is the average
in each line the first number is the temperature in Celsius and the second number is the time in minutes. The average numbers were found by adding up each of the numbers together and dividing by four. (27 + 17 + 12 +8) / 4 = 16. 100/4 = 25.
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Those are average values of the temperature and the clock time. However they are not average rates of change.
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