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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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: somewhere in the vicinity of 7 cm/s
Without further information, why is this just a guess?
answer/question/discussion: because we don't know how many changes in speed occurred between the starting velocity and ending velocity
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: 18 cm
This answer was arrived at by using the difference between the two velocities (6 cm/s) and multiplying that by the time interval (3 s). The seconds cancel, leaving 18 cm.
Using this reasoning a car moving at a constant 60 mph never gets anywhere. The difference in its velocities over any interval is 0.
It's not the difference in velocities, the average velocity that determines the displacement.
At what average rate did its velocity change with respect to clock time during this interval?
answer/question/discussion: 6 cm/s
The average rate at which the velocity changed with respect to clock time is equal to the change in distance divided by the change in clock time: 18 cm / 3 s = 6 cm/s
this is the ave rate of change of position with respect to clock time
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10 minutes
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&#At least part of your solution does not agree with the solution and comments given at the link below. You should view the solution at that link and self-critique as indicated there.
Solution
This link also expands on these topics and alerts you to many of the common errors made by students in the first part of this course. &#