cq_1_011

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PHY 201

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: ->->->->->->->->->->->-> (start in the next line):

Quantity A which is the distance the ball traveled is 10cm (20cm - 10cm). Quantity B is 5

seconds, because 9sec - 4sec = 5 sec. The ave rate of change of A with respect to B is 10 / 5

or 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: ->->->->->->->->->->->-> (start in the next line):

40 cm/sec - 10 cm/sec = 30 cm/sec / 3 seconds (change in clock time given) equals an

average rate of change of 10 cm/second.

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@&

Watch the units.

30 cm/s / (3 s) = 10 cm/s^2, not 10 cm/s.

Otherwise good.

*@

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):

5 cm/sec * 10seconds = a position change of 50 cm

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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):

In algebra I learned that rate is the average calculated by the change in A (or Y) over the

change in B (x). I was taught to think of 'over' as the division sign between the two. I believe

the concept is the same, even if worded slightly differently.

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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):

The average rate of change in velocity of given data A with respect to given data B is

calculated by taking the change in A (usually position) and then the change in B value (time in

the examples above). The resulting factor is the v Ave

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Copy and paste your work into the box below and submit as indicated:

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20 minutes

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