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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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: ->->->->->->->->->->->-> : I would say that the ball’s average velocity is greater than 6cm/sec but less than 8cm/sec.
• Without further information, why is this just a guess?
answer/question/discussion: ->->->->->->->->->->->-> : This is just a guess because we don’t know the length of time that the ball was in motion or how far it traveled, so we can’t actually calculate the average velocity because those specific value are needed for vAve = `ds/`dt.
• 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: ->->->->->->->->->->->-> : The ball travels at least 12cm, because the minimum velocity is 4cm/sec, but less than 30cm/sec, because that maximum of 10cm/sec wasn’t achieved until the very end. My best guess would be 21cm.
• At what average rate did its velocity change with respect to clock time during this interval?
answer/question/discussion: ->->->->->->->->->->->-> : Since the time interval was 3 seconds, 10-4 = 6/3 = an average change of +2cm/sec.
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10 minutes.
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Mostly very good, but you have the wrong units on your last answer, you've done your calculations without including the units at every step of the calculation, and your answers to some of the other questions could use revision. Sounds like a lot but it shouldn't take you more than 5 minutes.
&#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. &#