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PHY 201
Your 'cq_1_07.1' 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 falls freely from rest at a height of 2 meters.
Observations indicate that the ball reaches the ground in .64
seconds.
Based on this information what is its acceleration?
answer/question/discussion: ->->->->->->->->->->->-> :
Acceleration of an object due to gravity is assumed to be constant at 9.80 m/s.
In this problem acceleration due to gravity would be closer to 6.25 m/s^2. s = (at/2) + v0t
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@& s = (at/2) + v0t is not a correct equation. Double-check that. Among other things the units don't work out.
The average velocity is easily found to be about 3 m/s. Init vel is zero so final vel must be about 6 m/s. Change in vel will therefore also be 6 m/s, since init vel is zero. DIviding change in vel by time interval you get (6 m/s) / (.64 s) = 9 m/s^2, very approximately.
If you use equations, you should check them by reasoning (at least in the cases where this is possible). If you use reasoning, it's a good idea to check using the equations. You don't have time to do this on every problem, but you should do a good number of problems in this manner.
In all cases you should use units throughout your analysis.
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Is this consistent with an observation which concludes that a
ball dropped from a height of 5 meters reaches the ground in 1.05
seconds?
answer/question/discussion: ->->->->->->->->->->->-> :
I came up with 1.02 seconds.
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Are these observations consistent with the accepted value of the
acceleration of gravity, which is 9.8 m / s^2?
answer/question/discussion: ->->->->->->->->->->->-> :
The answers above are not consistent with acceleration being 9.8 m/s^2.
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&#See any notes I might have inserted into your document, and before looking at the link below see if you can modify your solutions. If there are no notes, this does not mean that your solution is completely correct.
Then please compare your old and new 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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