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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.
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cq_1_011
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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.
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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: ->->->->->->->->->->->-> n: ->->->->->->->->->->->-> n (start in the next line):
(20cm-10cm)/(9s-4s) = 10cm/5s = 2cm/sec
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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: ->->->->->->->->->->->-> n: ->->->->->->->->->->->-> n (start in the next line):
(40cm-10cm)/3s = 10cm/sec
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okay, I missed that we were dealing in velocity and not distance (didn't thoroughly read the problem)
ave rate = change in velocity / change in clock time =
(40cm/sec - 10cm/sec)/3sec
=10cm/sec /s
=10cm/s)*(1/s)
=10cm/s^2
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40 cm and 10 cm might represent distances or displacements. However no distances or displacements were given on this question. So 40 cm and 10 cm are not quantities that would be used in this calculation.
There were velocities of 40 cm/s and 10 cm/s, and a time interval of 3 s. These are the quantities that should go into your calculation.
This will also affect the units of your result.
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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: ->->->->->->->->->->->-> n: ->->->->->->->->->->->-> n (start in the next line):
5cm*10s = 50cm
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change is pos. = avg. rate * change in clock time
5cm/sec * 10sec = 50cm
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5 cm * 10 s = 50 cm * s, not 50 cm.
Howeverf 5 cm is not a distance or displacement associated with this question.
Of course 5 cm/s is an average rate of position change given in the question, so it should be clear how to modify this 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: ->->->->->->->->->->->-> n: ->->->->->->->->->->->-> n (start in the next line):
I have written the definition down and memorized it.
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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: ->->->->->->->->->->->-> n: ->->->->->->->->->->->-> n (start in the next line):
Take the change in variable a and divide it by the change in variable b to arrive at the average rate of change of a with respect to b.
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&#Very good responses. Let me know if you have questions. &#