course PHY 201 When you push the notes button, is everything supposed to just disappear? This kind of scared me alittle bit and I am concerned if you were able to get my answers or not when I pressed this button. SoGՀassignment #001 001. Rates qa rates 06-03-2008 ̬|X˻rH assignment #001 001. Rates qa rates 06-03-2008 OŤ⳧ assignment #001 001. Rates qa rates 06-03-2008
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18:13:49 `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 --> These instructions should be kept for future reference (which I have done). In order to get to from one question to the next or to a question's answer you should click the next question/answer button. Before you click for an answer, you should give your best answer in the box under the enter response button. When this is done, you can click this button to view your answer. If you are correct or incorrect, you can revise your answer or restate what you learned in your critique. These notes can be saved for future reference by using the save as notes button. You press the enter response buttont to send your critique and proceed to the next question. confidence assessment: 3
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18:14:06 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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18:20:13 `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 / 5 hrs= 10 dollars per hr is the rate at which you are earning a salary. In order to get this, you take the total of 50 dollars and divide it by the amount of time it took to earn the fifty dollars, the 5 hours, which yields a total of 10 dollars an hour. confidence assessment: 3
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18:21:41 The rate at which you are earning money is the number of dollars per hour you are earning. You are earning money at the rate of 50 dollars / (5 hours) = 10 dollars / hour. It is very likely that you immediately came up with the $10 / hour because almosteveryone is familiar with the concept of the pay rate, the number of dollars per hour. Note carefully that the pay rate is found by dividing the quantity earned by the time required to earn it. Time rates in general are found by dividing an accumulated quantity by the time required to accumulate it. You need to make note of anything in the given solution that you didn't understand when you solved the problem. If new ideas have been introduced in the solution, you need to note them. If you notice an error in your own thinking then you need to note that. In your own words, explain anything you didn't already understand and save your response as Notes.
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RESPONSE --> I got this answer correct and recognized that in order to determine a pay rate the amount earned is divided by the time required to earn it. confidence assessment: 3
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18:24:04 `q003.If you make $60,000 per year then how much do you make per month?
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RESPONSE --> Similarly, you need to determine a pay rate of the total you earn, $60,000, divided by the total time it took to earn it, a year or 12 months. 60,000 divided by 12 is 5,000. or $5,000 per month. confidence assessment: 3
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18:26:10 06-03-2008 18:26:10 Most people will very quickly see that we need to divide $60,000 by 12 months, giving us 60,000 dollars / (12 months) = 5000 dollars / month. Note that again we have found a time rate, dividing the accumulated quantity by the time required to accumulate it. You need to make note of anything in the given solution that you didn't understand when you solved the problem. If new ideas have been introduced in the solution, you need to note them. If you notice an error in your own thinking then you need to note that. In your own words, explain anything you didn't already understand and save your response as Notes.
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NOTES -------> I got the solution correct and understand the way it was obtained, however, I am not quite sure about the whole ""Notes"" thing, so I am writing this so I can see how it works. This is a pay rate problem, so you again need to divide the amount by the time it took to earn it.
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18:28:43 `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 --> If it were a small business it would be more appropriate to say it makes an average of $5,000 a month. No business will make exaclty this amount each month, no more or less ( some months may be alot more and some alot less). However it is likely that over a period of a year they can average about this amount. confidence assessment: 3
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18:30:59 Small businesses do not usually make the same amount of money every month. The amount made depends on the demand for the services or commodities provided by the business, and there are often seasonal fluctuations in addition to other market fluctuations. It is almost certain that a small business making $60,000 per year will make more than $5000 in some months and less than $5000 in others. Therefore it is much more appropriate to say that the business makes and average of $5000 per month. You need to make note of anything in the given solution that you didn't understand when you solved the problem. If new ideas have been introduced in the solution, you need to note them. If you notice an error in your own thinking then you need to note that. In your own words, explain anything you didn't already understand and save your response as Notes.
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RESPONSE --> I got this answer correct and understand that it makes more sense to say a business averaged $5,000 a month because the amount of business they get would fluctuate. I do not understand where all my stuff went after I pressed notes last time because everything disappeared. I will put this information on the work submit form to find iut if it is normal though. confidence assessment: 3
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18:39:43 `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 --> You would take the total distnace you had traveled , 300 miles, and divide this by the time it took you to cover this mileage, 6 hours. This would yield 50 miles/hr or 50 miles per hour that you traveled on average. You would say that this was your average rate because it is likely that during your journey there were times that you went faster and slower than 50 miles and hr, so this would just be your average rate over the distance in the specified amount of time. confidence assessment: 3
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18:40:49 The average rate is 50 miles per hour, or 50 miles / hour. This is obtained by dividing the accumulated quantity, the 300 miles, by the time required to accumulate it, obtaining ave rate = 300 miles / ( 6 hours) = 50 miles / hour. Note that the rate at which distance is covered is called speed. The car has an average speed of 50 miles/hour. We say 'average rate' in this case because it is almost certain that slight changes in pressure on the accelerator, traffic conditions and other factors ensure that the speed will sometimes be greater than 50 miles/hour and sometimes less than 50 miles/hour; the 50 miles/hour we obtain from the given information is clearly and overall average of the velocities. You need to make note of anything in the given solution that you didn't understand when you solved the problem. If new ideas have been introduced in the solution, you need to note them. If you notice an error in your own thinking then you need to note that. In your own words, explain anything you didn't already understand and save your response as Notes.
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RESPONSE --> I understand how I came to my correct conclusion. This is another similar rate problem to the ones that have been presented earlier. confidence assessment: 3
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18:43:44 `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 --> Over the course of the 1200 mile trip, you would be using 0.05 gallons per mile you drove. This is obtained by taking the total gallons and dividing them by the miles on the trip. confidence assessment: 3
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18:46:28 The rate of change of one quantity with respect to another is the change in the first quantity, divided by the change in the second. As in previous examples, we found the rate at which money was made with respect to time by dividing the amount of money made by the time required to make it. By analogy, the rate at which we use fuel with respect to miles traveled is the change in the amount of fuel divided by the number of miles traveled. In this case we use 60 gallons of fuel in 1200 miles, so the average rate it 60 gal / (1200 miles) = .05 gallons / mile. Note that this question didn't ask for miles per gallon. Miles per gallon is an appropriate and common calculation, but it measures the rate at which miles are covered with respect to the amount of fuel used. Be sure you see the difference. Note that in this problem we again have here an example of a rate, but unlike previous instances this rate is not calculated with respect to time. This rate is calculated with respect to the amount of fuel used. We divide the accumulated quantity, in this case miles, by the amount of fuel required to cover those miles. Note that again we call the result of this problem an average rate because there are always at least subtle differences in driving conditions that require the use of more fuel on some miles than on others. It's very important to understand the phrase 'with respect to'. Whether the calculation makes sense or not, it is defined by the order of the terms. In this case gallons / mile tells you how many gallons you are burning, on the average, per mile. This concept is not as familiar as miles / gallon, but except for familiarity it's technically no more difficult. You need to make note of anything in the given solution that you didn't understand when you solved the problem. If new ideas have been introduced in the solution, you need to note them. If you notice an error in your own thinking then you need to note that. In your own words, explain anything you didn't already understand and save your response as Notes.
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RESPONSE --> I got this answer correct becaue I did notice that the question was asking for the rate of miles covered with respect to the fuel used and not asking for the miles per gallon. confidence assessment: 3
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18:49:41 `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 average rates that we are obtaining are averages because they are not static. Such as in the question about the small business, there are times when businesses make more money and times when they make less money. No business would make exactly $5,000 every month. Likewise, the rates that we have been obtaining are variable, whish is why we call them average rates. confidence assessment: 3
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18:51:37 The word 'average' in the context of the dollars / month, miles / gallon types of questions we have been answering was used because we expect that in different months different amounts were earned, or that over different parts of the trip the gas mileage might have varied, but that if we knew all the individual quantities (e.g., the dollars earned each month, the number of gallons used with each mile) and averaged them in the usual manner, we would get the .05 gallons / mile, or the $5000 / month. In a sense we have already added up all the dollars earned in each month, or the miles traveled on each gallon, and we have obtained the total $60,000 or 1200 miles. Thus when we divide by the number of months or the number of gallons, we are in fact calculating an average rate. You need to make note of anything in the given solution that you didn't understand when you solved the problem. If new ideas have been introduced in the solution, you need to note them. If you notice an error in your own thinking then you need to note that. In your own words, explain anything you didn't already understand and save your response as Notes.
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RESPONSE --> I got this question correct, and even used the same example! I am quite sure that my thinking was most definitely correct, but as it is stated before, it is important to notice that these values are expected to be variable and that is why we call them averages. confidence assessment: 3
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19:22:28 `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 --> I think that in this problem the amount of pushups is to be divided by the average weight lifted for each group. When this is done in the first group you get 10/147= 0.068 and in the second group you get 50/162=0.308 to get the average rate of increase per daily pushup. confidence assessment: 1
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19:24:10 The second group had 15 pounds more lifting strength as a result of doing 40 more daily pushups than the first. The desired rate is therefore 15 pounds / 40 pushups = .375 pounds / pushup. You need to make note of anything in the given solution that you didn't understand when you solved the problem. If new ideas have been introduced in the solution, you need to note them. If you notice an error in your own thinking then you need to note that. In your own words, explain anything you didn't already understand and save your response as Notes.
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RESPONSE --> I see now, the 15 lb difference should be divided by the additional 40 pushups, which would give the rate of puonds per pushup. I was just thinking about this problem all wrong. confidence assessment: 1
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19:28:23 `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 --> I think that this one is similar to the previous question, but I am not quite sure. If it is, then the 17 lb difference in lifting between the two groups should be divided by the additional 20lbs in order to get a rate increase average of 0.85. confidence assessment: 2
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19:30:18 The difference in lifting strength was 17 pounds, as a result of a 20 pound difference in added weight. The average rate at which strength increases with respect added weight would therefore be 17 lifting pounds / (20 added pounds) = .85 lifting pounds / added pound. The strength advantage was .85 lifting pounds per pound of added weight, on the average. You need to make note of anything in the given solution that you didn't understand when you solved the problem. If new ideas have been introduced in the solution, you need to note them. If you notice an error in your own thinking then you need to note that. In your own words, explain anything you didn't already understand and save your response as Notes.
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RESPONSE --> I was correct. By dividing the lifting pound difference by the weight difference, a rate of an average .85 lifting pounds oer pound of weight ins gained. confidence assessment: 3
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19:33:44 `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 --> If the difference in the time is divided by the difference in the length (10 sec/100 meters), then an average rate of 0.1 seconde per meter can be obtained for the runner between the 100 and 200 meter marks. confidence assessment: 3
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19:36:33 The runner traveled 100 meters between the two positions, and required 10 seconds to do so. The average rate at which the runner was covering distance was therefore 100 meters / (10 seconds) = 10 meters / second. Again this is an average rate; at different positions in his stride the runner would clearly be traveling at slightly different speeds. You need to make note of anything in the given solution that you didn't understand when you solved the problem. If new ideas have been introduced in the solution, you need to note them. If you notice an error in your own thinking then you need to note that. In your own words, explain anything you didn't already understand and save your response as Notes.
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RESPONSE --> I got this exactly backward and I wasn't sure why, however, upon further inspection I now see and understand that I should have divided the total distance by the total time, sort of like any other rate problem instead of doing it the other way around. I think that I misread what the problem was asking for. confidence assessment: 2
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19:41:59 `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 --> I'm not quite sure how to set this up, but I am giving it my best educated guess. I think that the runner would take about 9.5 seconds to run 100 meters because the are running an average of 9.5 seconds between the 100 to 200 meter distance. confidence assessment: 1
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19:43:37 At 10 meters/sec, the runner would require 10 seconds to travel 100 meters. However the runner seems to be slowing, and will therefore require more than 10 seconds to travel the 100 meters. We don't know what the runner's average speed is, we only know that it goes from 10 m/s to 9 m/s. The simplest estimate we could make would be that the average speed is the average of 10 m/s and 9 m/s, or (10 m/s + 9 m/s ) / 2 = 9.5 m/s. Taking this approximation as the average rate, the time required to travel 100 meters will be (100 meters) / (9.5 m/s) = 10.5 sec, approx.. Note that simply averaging the 10 m/s and the 9 m/s might not be the best way to approximate the average rate--for example we if we knew enough about the situation we might expect that this runner would maintain the 10 m/s for most of the remaining 100 meters, and simply tire during the last few seconds. However we were not given this information, and we don't add extraneous assumptions without good cause. So the approximation we used here is pretty close to the best we can do with the given information. You need to make note of anything in the given solution that you didn't understand when you solved the problem. If new ideas have been introduced in the solution, you need to note them. If you notice an error in your own thinking then you need to note that. In your own words, explain anything you didn't already understand and save your response as Notes.
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RESPONSE --> I got this problem correct and undrstand why this really is the only course of action to take because we really don't have all the necessary information to make a more accurate assumption about the behavior of the runner. confidence assessment: 2
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19:44:53 `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 --> We did this now because we only have specific points of data in reference to how the runner runs to go by to assess information about how he/she runs. confidence assessment: 3
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19:46:15 In previous examples the quantities weren't rates. We were given the amount of change of some accumulating quantity, and the change in time or in some other quantity on which the first was dependent (e.g., dollars and months, miles and gallons). Here we are given 2 rates, 10 m/s and 9 m/s, in a situation where we need an average rate in order to answer a question. Within this context, averaging the 2 rates was an appropriate tactic. You need to make note of anything in the given solution that you didn't understand when you solved the problem. If new ideas have been introduced in the solution, you need to note them. If you notice an error in your own thinking then you need to note that. In your own words, explain anything you didn't already understand and save your response as Notes.
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RESPONSE --> That is exactly what I meant. We had two specific rates, which can be averaged, rather than before when we were given a change in time of quantities. confidence assessment: 3
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