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Phy 201
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: ->->->->->->->->->->->-> (start in the next line):
The average velocity of the of the ball is increasing at an increasing rate so the velocity will always be positive.
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This is a good conjecture, but you can be more specific.
How many cm/sec would you think is the most likely average velocity?
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Without further information, why is this just a guess?
answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):
Because not enough information is given in order to give a more definite response like how we got to the two velocities.
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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):
10cm/sec - 4cm/sec = 6cm/sec = increase in velocity
6cm/sec / 3sec = 2cm
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However the answer to 'how far did the object travel' is not directly related to the change in velocity. An object can move a significant distance at a constant velocity, in which case there is no change, or at a changing velocity.
In any case, this object moves at no less than 4 cm/sec, for 3 seconds. So clearly it moves more than 2 cm.
To make a good estimate you'll need to estimate the average velocity (see my first note), and base your result on that estimate.
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Your calculation does give you the change in velocity divided by the change in clock time, except that cm/sec divided by sec is cm/sec * 1/sec. This gives you cm/s^2, not 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):
10cm/sec - 4cm/sec = 6cm/sec
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This is the change in velocity.
On the preceding question you came very close to finding the average rate of change of the velocity with respect to clock time.
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