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Phy 231
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?
answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):
vAve = (v0 + vf) / 2
vAve = average velocity; v0 = initial velocity; vf = final velocity
vAve = (4 cm/s + 10 cm/s) / 2 = 14 cm/s / 2 = 7 cm/s
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Without further information, why is this just a guess?
answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):
This is just a guess because we dont know over what time interval the velocity changed.
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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: ->->->->->->->->->->->-> (start in the next line):
ds = (vAve)*(dt) and
ds = change in position; vAve = average velocity; dt = change in time
ds = ?
vAve = 7 cm/s (calculated in previous question)
dt = 3 s
ds = (7 cm/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: ->->->->->->->->->->->-> (start in the next line):
average rate velocity changes = average acceleration = a
a = dv / dt
dv = change in velocity = final velocity initial velocity = 10 cm/s 4 cm/s = 6 cm/s
dt = 3 s
a = (6 cm/s) / 3 s = 2 cm/s^2
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15 min
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&#Very good responses. Let me know if you have questions. &#