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.
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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?
(4 cm/sec + 10 cm/sec) / 2 = (14 cm/sec) / 2 = 7 cm/sec
answer/question/discussion: ->->->->->->->->->->->-> :
• Without further information, why is this just a guess?
This is just a guess because I do not know how long it took the ball to go from the beginning point to the end point and because an average is not an exact measurement.
answer/question/discussion: ->->->->->->->->->->->-> :
• 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: ->->->->->->->->->->->-> :
vAve = `ds / `dt
vAve * `dt = `ds
(7 cm/sec) * (3 sec) = `ds
21 cm = `ds
My best guess is that the ball traveled 21 cm in those 3 seconds.
• At what average rate did its velocity change with respect to clock time during this interval?
answer/question/discussion: ->->->->->->->->->->->-> :
`dv = rate of `dv * `dt
6 cm/sec = rate of `dv * (3 seconds)
(6 cm/sec) / (3 seconds) = rate of `dv
2 cm/sec = rate of `dv
Your units aren't quite right
The average rate at which the velocity changed with respect to clock time is 2 cm/sec.
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10 minutes
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I am not certain that I am calculating the rate of change in velocity correctly. I understand the concept, but not how to apply the formula. Am I using the formula correctly?
You've got the right ideas. Check the link:
&#Please compare your solutions with the expanded discussion at the link
Solution
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