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Phy 121
Your 'cq_1_01.1' 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_01.1_labelMessages **
The problem:
Here is the definition of rate of change of one quantity with respect to another:
The average rate of change of A with respect to B on an interval is
average rate of change of A with respect to B = (change in A) / (change in B)
Apply the above definition of average rate of change of A with respect to B to each of the following. Be sure to identify the quantity A, the quantity B and the requested average rate.
If the position of a ball rolling along a track changes from 10 cm to 20 cm while the clock time changes from 4 seconds to 9 seconds,
what is the average rate of change of its position with respect to clock time during this interval?
answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):
A = Change in position of ball = 10 cm
B = Change in clock time = 5 seconds
The average rate of change of its position with respect to clock time is 10 cm / 5 seconds = 5 cm / second.
The average rate is 2 cm / second
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If the velocity of a ball rolling along a track changes from 10 cm / second to 40 cm / second during an interval during which the clock time changes by 3 seconds,
then what is the average rate of change of its velocity with respect to clock time during this interval?
answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):
A = Change in velocity = 30 cm
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30 cm is a position or a change in position, not a velocity or a change in velocity.
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B = change in clock time = 3 seconds
The average rate of change of its velocity is 30 cm / 3 seconds = 10 cm / second
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cm/second is a unit of velocity, not a unit of rate of change of velocity.
If you get the unit of velocity right, and then do your units calculation correctly, you'll end up with the right units for this quantity.
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The average rate is 10 cm / second.
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If the average rate at which position changes with respect to clock time is 5 cm / second, and if the clock time changes by 10 seconds, by how much does the position change?
answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):
The position changes by 50 cm.
5 cm * 10 seconds = 50 cm.
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5 cm * 10 second = 50 cm * seconds, not 50 cm.
However the average velocity isn't 5 cm, it's 5 cm/second.
Again if you do the units calculations correctly you'll get a good result.
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You will be expected hereafter to know and apply, in a variety of contexts, the definition given in this question. You need to know this definition word for word.
If you try to apply the definition without using all the words it is going to cost you time and it will very likely diminish your performance.
Briefly explain how you will ensure that you remember this definition.
answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):
I will write it down and memorize it. I will write it on my dry erase board and see it every time I go out. I will recite it every day at least once and practice it with some problems as well.
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You are asked in this exercise to apply the definition, and given a general procedure for doing so.
Briefly outline the procedure for applying this definition, and briefly explain how you will remember to apply this procedure.
answer/question/discussion: ->->->->->->->->->->->-> (start in the next line):
If I am understanding what I am suppose to be doing for this then the way to apply the defintion to a given procedure is to find out what the quantity for A is and B.
Then after receiving both A and B then proceed to figure out what it the average is by plugging both quantities in the correct place.
I will remember that A respect to B so A over B when dividing it to get the answer.
The way I would remember to apply this procedure is to practice.
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Copy and paste your work into the box below and submit as indicated:
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25 minutes
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I can tell what you're thinking, and you are using the definition correctly.
However you don't have the correct units on some of your quantities.
&#Please see my notes and submit a copy of this document with revisions, comments and/or questions, and mark your insertions with &&&& (please mark each insertion at the beginning and at the end).
Be sure to include the entire document, including my notes. &#
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