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Phy 121
Your 'cq_1_06.1' 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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For each situation state which of the five quantities v0, vf, `ds, `dt and a are given, and give the value of each.
• A ball accelerates uniformly from 10 cm/s to 20 cm/s while traveling 45 cm.
answer/question/discussion: ->->->->->->->->->->->-> :
v0 = 10 cm/s
vf = 20 cm/s
‘ds = 45 cm
‘dt = (45 cm)/(15 cm/s) = 3 seconds
A = (20 cm/s – 10 cm/s)/3 seconds = (10 cm/s)/3 seconds = 3.33 cm/s/s
• A ball accelerates uniformly at 10 cm/s^2 for 3 seconds, and at the end of this interval is moving at 50 cm/s.
answer/question/discussion: ->->->->->->->->->->->-> :
v0 = 20 cm/s
vf = 50 cm/s
‘ds = 45 cm
‘dt = 3 seconds
A = 10 cm/s/s
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• A ball travels 30 cm along an incline, starting from rest, while accelerating at 20 cm/s^2.
answer/question/discussion: ->->->->->->->->->->->-> :
v0 = 0 cm/s
vf = 16.33 cm/s
‘ds = 30 cm
‘dt = 0.816 seconds
A = 20 cm/s^2
You've identified v0, `ds and a correctly, which is the main point of this question.
However if vf = 16.33 cm/s, then vAve = 8.17 cm/s and it will take 30 s / (8.17 cm/s) = 3.6 seconds or so to travel the 30 cm. Not consistent with your `dt.
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Then for each situation answer the following:
• Is it possible from this information to directly determine vAve?
answer/question/discussion: ->->->->->->->->->->->-> :
As long as you have the initial and final velocity, you can determine vAve. In addition, you can determine vAve, if you have ‘ds and ‘dt
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• Is it possible to directly determine `dv?
answer/question/discussion: ->->->->->->->->->->->-> :
As long as you have the initial and final velocity, you can determine ‘dv. In addition, you can determine ‘dv, if you have a and ‘dt
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Unknown
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Good job with identifying the quantities. One of your calculations is not correct, so be sure to see my note for future reference.