#$&*
Phy 231
Your 'cq_1_07.1' report has been received. Scroll down through the document to see any comments I might have inserted, and my final comment at the end.
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7/21/11 2:31 pm
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10 min
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A ball falls freely from rest at a height of 2 meters.
Observations indicate that the ball reaches the ground in .64
seconds.
Based on this information what is its acceleration?
answer/question/discussion: ->->->->->->->->->->->-> :
ds = v0 * dt + .5 * a * dt^2
2m = (0)*0.64s + 0.5 * a * 0.64^2 s^2
2m = 0 + 0.5 * a * 0.4096s^2
0.5 * a = 2m / 0.4096 s^2
0.5 * a = 4.883 m/s/s
a = 4.883/0.5 m/s/s
a = 9.77 m/s/s
#$&*
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: ->->->->->->->->->->->-> :
ds = v0 * dt + .5 * a * dt^2
5m = (0) * 1.05s + 0.5 * a * 1.05^2 s^2
5m = 0 + 0.5 * a * 1.1025s^2
0.5 * a = 4.535 m/s/s
a = 9.07m/s/s
#$&*
Are these observations consistent with the accepted value of the
acceleration of gravity, which is 9.8 m / s^2?
answer/question/discussion: ->->->->->->->->->->->-> :
The first on is closer to 10.0 m/s/s and the other one is closer
to 9.0 m/s/s
Gravity = 9.8 m/s/s so no these are not really very close at
all.
#$&*
&#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. &#
@& Good use of the equations, and good answers throughout, but check the discussion at the link for a much more direct way to reason out the solution.*@