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.
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cq_1_021
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.
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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 would guess that the ball was traveling at a rate of 1cm/sec.
It never goes less that 4 cm/s or more than 10 cm/s, so its average velocity wouldn't be 1 cm/s.
&&&&To determine the average velocity of the ball, we will use the method of determining the velocity at the halfway point. So 4cm/s+ 10cm/s= 14 cm/s / 2 = 7 cm/s &&&&
#$&*
• Without further information, why is this just a guess?
answer/question/discussion: ->->->->->->->->->->->-> : ->->->->->->->->->->->-> (start in the next line):
This is only a guess as we are not provided with the actual change in distance. We are only provided with the change in time.
&&&& In addition to not being provided with more information, this guess is just an estimate because the velocity of the ball could be changing at a non uniform rate. &&&
#$&*
• 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):
Based on the given information, I would guess that the item traveled 3 cm.
&&&&To solve this, we would need to use the velocity determined earlier, by the time given in this question. We will follow the equation of change in position = average velocity * change in clock time. So 7cm/s * 3 cm/s = 21 cm. &&&&
#$&*
• At what average rate did its velocity change with respect to clock time during this interval?
answer/question/discussion: ->->->->->->->->->->->-> : ->->->->->->->->->->->-> (start in the next line):
As the information is not specific, we can only make a guess as to what the average rate is. If the object changes 3 cm (guess) in distance and it takes it 3 seconds to travel, then we divide the change in a / change in b. This would give us 1 cm/ sec. However, this answer cannot be taken as accurate as it is a guess.
&&&&To determine the average rate of velocity we must determine the change in position and divide it by the change in clock time. Our change in position is determined by 10cm/s-4cm/s = 6 cm/s. If our change in time is 3cm/s then 6cm/s / 3 cm/s = 2cm/s^2 &&&&
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15 minutes
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&#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. &#
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This is a resubmission of seed question 2.1 after revisions were made.
&#This looks very good. Let me know if you have any questions. &#