rates

course Phy 201

001. Ratesqa rates

Your work has been received. Please scroll through the document to see any inserted notes (inserted at the appropriate place in the document, in boldface) and a note at the end. The note at the end of the file will confirm that the file has been reviewed; be sure to read that note. If there is no note at the end, notify the instructor through the Submit Work form, and include the date of the posting to your access page.

01-11-2008

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10:42:07

`q001. You should copy and paste these instructions to a word processor for reference. However you can always view them, as well as everything else that has appeared in this box, by clicking the 'Display Everything' button.

1. For the next question or answer, you click on 'Next Question / Answer' button above the box at top left until a question has been posed. Once a question has been posed you are to answer before you click again on this button.

2. Before clicking for an answer, type your best answer to the current question into the box to the right, then clip on the 'Enter Answer' button.

3. After entering your answer you will click on 'Next Question / Answer' to view the answer to the question. Do not tamper with the information displayed in the left-hand box.

4. If your answer was incorrect, incomplete or would otherwise require revision, you will enter a self-critique. If you learned something from the answer, you need to restate it in your own words in order to reinforce your learning. If there is something you feel you should note for future reference, you should make a note in your own words. Go to the response box (the right-hand box) and type in a self-critique and/or notes, as appropriate. Do not copy and paste anything from the left-hand box, since that information will be saved in any case.

5. If you wish to save your response to your Notes file you may choose to click on the 'Save As Notes' button rather than the 'Enter Answer' button. Doing so will save your work for your future reference. Your work will be saved in a Notes file in the c:\vhmthphy folder. The title of the Notes file will also include the name you gave when you started the program.

6. After clicking either the 'Enter Response' or the 'Save as Notes' button, click on 'Next Question / Answer' and proceed in a similar manner.

In the right-hand box briefly describe your understanding of these instructions, then click 'Enter Answer'.

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RESPONSE -->

check

confidence assessment: 3

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10:42:21

Your answer has been noted. Enter 'ok' in the Response Box and click on Enter Response, then click on Next Question/Answer for the first real question.

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RESPONSE -->

ok

confidence assessment: 3

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10:43:29

`q002. Note that there are 10 questions in this assignment. The questions are of increasing difficulty--the first questions are fairly easy but later questions are very tricky. The main purposes of these exercises are to refine your thinking about rates, and to see how you process challenging information. Continue as far as you can until you are completely lost. Students who are prepared for the highest-level math courses might not ever get lost.

If you make $50 in 5 hr, then at what rate are you earning money?

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RESPONSE -->

$50 / 5hr = $10 / hr

confidence assessment: 3

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10:44:49

`q003.If you make $60,000 per year then how much do you make per month?

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RESPONSE -->

$60000 / 12 months = $5000 / month

confidence assessment: 3

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10:47:54

`q004. Suppose that the $60,000 is made in a year by a small business. Would be more appropriate to say that the business makes $5000 per month, or that the business makes an average of $5000 per month?

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RESPONSE -->

the business makes an average of $5000 / month

confidence assessment: 2

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10:52:25

`q005. If you travel 300 miles in 6 hours, at what average rate are you covering distance, and why do we say average rate instead of just plain rate?

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RESPONSE -->

50 miles / hr

your speed is not constant, but rather it is constantly changing (hills, valleys, traffic, air resistance)

confidence assessment: 2

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10:54:15

`q006. If you use 60 gallons of gasoline on a 1200 mile trip, then at what average rate are you using gasoline, with respect to miles traveled?

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RESPONSE -->

1200 miles / 60 gallons = 20 miles / gallon

confidence assessment: 3

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10:56:28

`q007. The word 'average' generally connotes something like adding two quantities and dividing by 2, or adding several quantities and dividing by the number of quantities we added. Why is it that we are calculating average rates but we aren't adding anything?

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RESPONSE -->

the totals required to find the averages are already given in the intitial problem

confidence assessment: 2

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11:03:15

`q008. In a study of how lifting strength is influenced by various ways of training, a study group was divided into 2 subgroups of equally matched individuals. The first group did 10 pushups per day for a year and the second group did 50 pushups per day for year. At the end of the year to lifting strength of the first group averaged 147 pounds, while that of the second group averaged 162 pounds. At what average rate did lifting strength increase per daily pushup?

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RESPONSE -->

147 / 356 = .413 pounds; 162 / 356 = .455 pounds

confidence assessment: 1

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11:05:02

`q009. In another part of the study, participants all did 30 pushups per day, but one group did pushups with a 10-pound weight on their shoulders while the other used a 30-pound weight. At the end of the study, the first group had an average lifting strength of 171 pounds, while the second had an average lifting strength of 188 pounds. At what average rate did lifting strength increase with respect to the added shoulder weight?

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RESPONSE -->

188 - 171 = 17 ; 17 / 20 pounds = .85

confidence assessment: 1

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11:09:40

`q010. During a race, a runner passes the 100-meter mark 12 seconds after the start and the 200-meter mark 22 seconds after the start. At what average rate was the runner covering distance between those two positions?

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RESPONSE -->

200 - 100 = 100meters; 22 - 12 = 10 seconds

100 meters / 10 seconds = 10 meters / s

confidence assessment: 1

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11:11:42

`q011. During a race, a runner passes the 100-meter mark moving at 10 meters / second, and the 200-meter mark moving at 9 meters / second. What is your best estimate of how long it takes the runner to cover the 100 meter distance?

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RESPONSE -->

100 meters / 9 meters per second = 11.1 s

confidence assessment: 2

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11:14:33

`q012. We just averaged two quantities, adding them in dividing by 2, to find an average rate. We didn't do that before. Why we do it now?

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RESPONSE -->

there were two different velocities and in order to find the average of the two we had to add then divide by 2

confidence assessment: 1

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See my previous note on using the right sequence of operations with the program. Your file should contain the given solutions and, when necessary, self-critiques.

No cause for concern regarding your knowledge. However you did get #6 backwards. Go back and 'click through' the program to see the given solution.

In case you missed the previous note on the operation of the program:

&#To run the program correctly you click on the Next Question/Solution button (top left), enter your response in the Answer box (the box at top right), click on the Enter Response button (above the top right box), then again on the Next Question/Solution botton (top left) to see the solution, and finally enter your response or self-critique in the Answer box and click on Enter Response.

You then start the process over with the next question, clicking on the Next Question/Solution button at top left, etc.

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