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phys 201
Your 'cq_1_04.1' 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 is moving at 10 cm/s when clock time is 4 seconds, and at 40 cm/s when clock time is 9 seconds.
• Sketch a v vs. t graph and represent these two events by the points (4 sec, 10 cm/s) and (9 s, 40 cm/s).
answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):
On my paper I sketched a v vs. t graph of (4 sec, 10 cm/s) and (9 s, 40 cm/s).
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• Sketch a straight line segment between these points.
answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):
I sketched a straight line segment between the two points
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• What are the rise, run and slope of this segment?
answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):
slope = (rise) / (run) = (y2 - y1) / (x2 - x1) = (40 - 10) / (9 - 4) = 6 cm/s
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You didn't include units in your calculation (40 - 10) / (9 - 4), and if the units of those quantities are included the calculation does not yield units of cm / s.
In correct units will strongly tend to confuse understanding and interpretation.
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• What is the area of the graph beneath this segment?
answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):
points/dimensions of triangle (4, 10), (9, 40), (9,10)
area of triangle = (30 * 5) / 2 = 75 cm2
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Again you need to include units throughout your calculation, and correctly work out the units of your result.
Note aso that the region beneath the segment includes the triangle you mention, but the triangle doesn't comprose the entire region.
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Overall this is pretty good, but you have some errors especially related to units.
You shouldn't have much trouble making the necessary revisions.
&#Please see my notes and, unless my notes indicate that revision is optional, submit a copy of this document with revisions 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.
If my notes indicate that revision is optional, use your own judgement as to whether a revision will benefit you.
Spend a reasonable amount of time on your revision, but don't let yourself get too bogged down. After a reasonable amount of time, if you don't have at least a reasonable attempt at a solution, insert the best questions you can showing me what you do and do not understand, and I'll attempt to clarify further. &#
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