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course Phy 201
9/24 6:30 pm
cq_1_021#$&*
Phy 201
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.
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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):
I believe that the balls change in velocity is 6cm/sec. This would tell me that the ball was probably rolling downwards and sped up as it got to the end of where it was going.
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• Without further information, why is this just a guess?
answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):
We were not given the average velocity or the complete distance the ball was rolling and how much time it took to get from one end to the other.
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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 would estimate the ball to have traveled at least 20 cm in distance.
this answer requires more detail, though it's a good estimate
&&&&This guess is not entirely correct. I now know that I can determine the average velocity by adding the initial and final and dividing by two. This would give me 4cm/s+10cm/s=14cm/s and dividing by 2=7cm/s. I would then use this average velocity and multiply it by the number of seconds given to determine that the object traveled 21 cm during the time interval.&&&&
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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):
The change in distance would be 6 cm and the change in clock time would be 3 seconds. The average rate of change in velocity would be 2 cm/sec.
there is no 6 cm distance involved here; there is a 6 cm/s change in velocity
It looks like you did the right calculation, but your units aren't correct and you haven't correctly identified all your quantities.
&&&&We would first use the change in velocity which is 10 cm/s-4 cm/s=6cm/s. We would then divide this by 3 seconds, which is the change in clock time to get 2 cm/s/s. (I am unsure why in the discussion the change in time is 2, when it states in a previous question that it takes 3 seconds to get from one velocity to the next. )&&&&
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Approx 10 minutes.
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Check the discussion at the link. Submit a revision if you're not 100% sure you understand.
&#See any notes I might have inserted into your document. If there are no notes, this does not mean that your solution is completely correct.
Then please compare your solutions with the expanded discussion at the link
Solution
Self-critique your solutions, if this is necessary, according to the usual criteria. Insert any revisions, questions, etc. into a copy of this posted document. Mark any insertions with &&&& so they can be easily identified.
If your solution is completely consistent with the given solution, you need do nothing further with this problem. &#
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&#Your work looks very good. Let me know if you have any questions. &#
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