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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.
** CQ_1_02.1_labelMessages.txt **
The problem:
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: ->->->->->->->->->->->-> scussion (start in the next line):
Best guess is that the vAve is 7 cm/s. The average of the initial velocity and the final velocity is (10cm/s + 4 cm/s)/2 or (14cm/s)/2 which is 7 cm/s
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Without further information, why is this just a guess?
answer/question/discussion: ->->->->->->->->->->->-> scussion (start in the next line):
This is just a guess, because we don't know if the velocity was changing at a constant rate. It could have been travelling most of the time at 50cm/s, which really would skew the vAve
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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: ->->->->->->->->->->->-> scussion (start in the next line):
Since our best guess was a vAve of 7cm/s and we have a time of 3 seconds we can use the formula `ds=vAve * `dt
`ds = 7cm/s * 3 s = 21 cm
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At what average rate did its velocity change with respect to clock time during this interval?
answer/question/discussion: ->->->->->->->->->->->-> scussion (start in the next line):
We need to find the change in velocity with respect to change in clock time
Change in velocity is 10 cm/s - 4 cm/s or 6cm/s.
Change in clock time is 3 sec.
(6cm/s)/3s = 2cm/s^2
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&#Very good responses. Let me know if you have questions. &#