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.
** **
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?
20cm-10cm=10cm (change in A)
9sec-4sec=5sec (change in B)
10/5=2cm per second (average rate of change)
answer/question/discussion:
• 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?
40cm-10cm=30cm
30/3=10cm per second
10 cm and 40 cm are not quantity associated with this problem. 10 cm/s and 40 cm/s are. The numbers come out as you indicate, but your units are incorrect. What are the units of the correct result?
answer/question/discussion:
• 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?
5x10=50cm
answer/question/discussion:
You need to include units in your calculation. The numbers 5 and 10, as you use them, do not include units and they should.
• 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.
I will try to repeat this definition and memorize it. Also, I will try to use it over and over to make sure I can remember it.
answer/question/discussion:
• 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.
The definition is the average rate of change of A with respect to B=(change in A)/(change in B). It can be applied in different ways depending on the question. Just like the above questions, you may have to subtract in order to get the change in A and B. Sometimes you may have to multiply in order to get the rate of change. If you have the definition memorized you can read the question and apply which ever equation that will give the correct result.
answer/question/discussion:
** **
25 minutes
** **
Except for some errors in units, your work is excellent. The correct use of units is essential, so you do need to correct those errors
&#Please see my notes and submit a copy of this document with revisions and/or questions, and mark your insertions with &&&&. &#