assignments

course phy 231

sent this one as one file because i think the others itried submitting didnt go through as i forgot to put the acces code.

???|??K?€?????assignment #001001. Only assignment: prelim asst

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.

qa prelim

???????????

assignment #001

qa prelim

qa prelim

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18:44:21

`questionNumber 10001

`q001. Part 1 includes six activities. If you have completed an activity, just enter the answer 'completed'.

This question is appearing in the Question box. The box to the right is the Answer box, where you will type in your answers to the questions posed here.

To use this program you read a question, then enter your answer in the Answer box and click on Enter Answer. In your answers give what is requested, but don't go into excruciating detail. Try to give just enough that the instructor can tell that you understand an item.

After entering an answer click on Next Question/Answer above the Question box.

Do you understand these instructions?

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RESPONSE -->

yes

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????g????????

assignment #001

001. typewriter notation

qa initial problems

12-27-2007

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20:07:38

`questionNumber 10000

`q001. Explain the difference between x - 2 / x + 4 and (x - 2) / (x + 4). The evaluate each expression for x = 2.

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RESPONSE -->

with the first expression. x-2/x+4 would be seperated from eachother. only 2 would be divided by x. so x would subract from 2/x then added to 4. the answer would be 5

with the second expression, the parenthesis shows that each expression is in a group. so x-2 would divide over x+4. the answer would be 0

confidence assessment: 3

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?o??????n?assignment #003

003. PC1 questions

qa initial problems

12-27-2007

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22:16:56

`questionNumber 30000

`q001 A straight line connects the points (3, 5) and (7, 17), while another straight line continues on from (7, 17) to the point (10, 29). Which line is steeper and on what basis to you claim your result?

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RESPONSE -->

confidence assessment:

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???P??????;????

assignment #003

003. PC1 questions

qa initial problems

12-27-2007

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22:30:35

`questionNumber 30000

`q001 A straight line connects the points (3, 5) and (7, 17), while another straight line continues on from (7, 17) to the point (10, 29). Which line is steeper and on what basis to you claim your result?

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RESPONSE -->

7,17 is steeper. as it is the central point and at that point as it goes to 10,29 it becomes less steep

confidence assessment: 1

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?????U???y???assignment #005

005. Calculus

qa initial problems

12-27-2007

???~???P??w??

assignment #003

003. Misc: Surface Area, Pythagorean Theorem, Density

qa areas volumes misc

12-31-2007

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15:11:06

`questionNumber 30000

`q001. There are 10 questions and 5 summary questions in this assignment.

What is surface area of a rectangular solid whose dimensions are 3 meters by 4 meters by 6 meters?

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RESPONSE -->

108

confidence assessment: 2

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15:13:06

`questionNumber 30000

`q002. What is the surface area of the curved sides of a cylinder whose radius is five meters and whose altitude is 12 meters? If the cylinder is closed what is its total surface area?

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RESPONSE -->

120

confidence assessment: 2

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15:15:08

`questionNumber 30000

`q003. What is surface area of a sphere of diameter three cm?

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RESPONSE -->

36

confidence assessment: 3

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15:18:04

`questionNumber 30000

`q004. What is hypotenuse of a right triangle whose legs are 5 meters and 9 meters?

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RESPONSE -->

106

confidence assessment: 2

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15:20:13

12-31-2007 15:20:13

`q005. If the hypotenuse of a right triangle has length 6 meters and one of its legs has length 4 meters what is the length of the other leg?

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NOTES ------->

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?b?~?????{?a?l???

assignment #003

003. Misc: Surface Area, Pythagorean Theorem, Density

qa areas volumes misc

12-31-2007

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16:16:15

`questionNumber 30000

`q005. If the hypotenuse of a right triangle has length 6 meters and one of its legs has length 4 meters what is the length of the other leg?

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RESPONSE -->

52

confidence assessment: 2

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16:23:21

`questionNumber 30000

`q006. If a rectangular solid made of a uniform, homogeneous material has dimensions 4 cm by 7 cm by 12 cm and if its mass is 700 grams then what is its density in grams per cubic cm?

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RESPONSE -->

2.08 cubic cm

confidence assessment: 2

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16:32:59

`questionNumber 30000

`q007. What is the mass of a sphere of radius 4 meters if its average density is 3,000 kg/cubic meter?

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RESPONSE -->

750

confidence assessment: 0

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16:37:30

`questionNumber 30000

`q008. If we build a an object out of two pieces of material, one having a volume of 6 cm^3 at a density of 4 grams per cm^3 and another with a volume of 10 cm^3 at a density of 2 grams per cm^3 then what is the average density of this object?

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RESPONSE -->

17

confidence assessment: 0

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16:39:26

`questionNumber 30000

`q009. In a large box of dimension 2 meters by 3 meters by 5 meters we place 27 cubic meters of sand whose density is 2100 kg/cubic meter, surrounding a total of three cubic meters of cannon balls whose density is 8,000 kg per cubic meter. What is the average density of the material in the box?

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RESPONSE -->

confidence assessment: 2

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16:39:49

`questionNumber 30000

`q010. How many cubic meters of oil are there in an oil slick which covers 1,700,000 square meters (between 1/2 and 1 square mile) to an average depth of .015 meters? If the density of the oil is 860 kg/cubic meter the what is the mass of the oil slick?

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RESPONSE -->

confidence assessment: 2

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16:42:09

`questionNumber 30000

`q011. Summary Question 1: How do we find the surface area of a cylinder?

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RESPONSE -->

2pi (radius)r (height)h + 2pir^2

confidence assessment: 3

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16:43:29

`questionNumber 30000

`q012. Summary Question 2: What is the formula for the surface area of a sphere?

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RESPONSE -->

S = 4pir^2

confidence assessment: 3

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16:44:50

`questionNumber 30000

`q013. Summary Question 3: What is the meaning of the term 'density'.

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RESPONSE -->

density is mass per unit volume

d=m/v

confidence assessment: 3

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16:48:55

`questionNumber 30000

`q014. Summary Question 4: If we know average density and mass, how can we find volume?

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RESPONSE -->

mass/density=v

confidence assessment: 2

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16:50:04

`questionNumber 30000

`q015. Explain how you have organized your knowledge of the principles illustrated by the exercises in this assignment.

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RESPONSE -->

i used my knowlede of density, mass and volume and there formulas to figure out the answers to the problems presented

confidence assessment: 2

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???????????P??

assignment #001

001. Areas

qa areas volumes misc

12-31-2007

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16:55:05

`questionNumber 10000

`q001. There are 11 questions and 7 summary questions in this assignment.

What is the area of a rectangle whose dimensions are 4 m by 3 meters.

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RESPONSE -->

confidence assessment:

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16:55:28

`questionNumber 10000

`q001. There are 11 questions and 7 summary questions in this assignment.

What is the area of a rectangle whose dimensions are 4 m by 3 meters.

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RESPONSE -->

4l*3w=12

confidence assessment: 3

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16:58:09

`questionNumber 10000

`q002. What is the area of a right triangle whose legs are 4.0 meters and 3.0 meters?

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RESPONSE -->

6=1/2base*height

confidence assessment: 3

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16:59:32

`questionNumber 10000

`q003. What is the area of a parallelogram whose base is 5.0 meters and whose altitude is 2.0 meters?

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RESPONSE -->

10.0=base*height

confidence assessment: 3

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17:00:35

`questionNumber 10000

`q004. What is the area of a triangle whose base is 5.0 cm and whose altitude is 2.0 cm?

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RESPONSE -->

5=1/2base*height

confidence assessment: 3

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17:04:58

`questionNumber 10000

`q005. What is the area of a trapezoid with a width of 4.0 km and average altitude of 5.0 km?

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RESPONSE -->

20

confidence assessment: 3

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17:05:58

`questionNumber 10000

`q006. What is the area of a trapezoid whose width is 4 cm in whose altitudes are 3.0 cm and 8.0 cm?

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RESPONSE -->

28

confidence assessment: 3

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17:07:12

`questionNumber 10000

`q007. What is the area of a circle whose radius is 3.00 cm?

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RESPONSE -->

28.27 = pir^2

confidence assessment: 3

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17:13:32

`questionNumber 10000

`q008. What is the circumference of a circle whose radius is exactly 3 cm?

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RESPONSE -->

3

confidence assessment: 2

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17:15:22

`questionNumber 10000

`q009. What is the area of a circle whose diameter is exactly 12 meters?

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RESPONSE -->

144

confidence assessment: 3

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17:17:07

`questionNumber 10000

`q010. What is the area of a circle whose circumference is 14 `pi meters?

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RESPONSE -->

196

confidence assessment: 1

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17:19:00

`questionNumber 10000

`q011. What is the radius of circle whose area is 78 square meters?

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RESPONSE -->

19104

confidence assessment: 0

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17:20:16

`questionNumber 10000

`q014. Summary Question 3: How do we calculate the area of a parallelogram?

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RESPONSE -->

multiply base by height to get the area

confidence assessment: 3

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17:21:58

`questionNumber 10000

`q015. Summary Question 4: How do we calculate the area of a trapezoid?

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RESPONSE -->

1/2 ?h ?area + base

confidence assessment: 3

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17:22:38

`questionNumber 10000

`q016. Summary Question 5: How do we calculate the area of a circle?

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RESPONSE -->

area of circle is Pi ?r2

confidence assessment: 3

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17:24:38

`questionNumber 10000

`q017. Summary Question 6: How do we calculate the circumference of a circle? How can we easily avoid confusing this formula with that for the area of the circle?

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RESPONSE -->

pi *diameter of a cricle. to differentiate between the area and circumfereance of a circle, is that area involves radius while the circumference deals with the diameter

confidence assessment: 3

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17:26:13

`questionNumber 10000

`q018. Explain how you have organized your knowledge of the principles illustrated by the exercises in this assignment.

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RESPONSE -->

i tried to use what i know in finding an area of an object. either using its height, radius, base, altitude, etc

confidence assessment: 3

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???O?????????

assignment #002

002. Volumes

qa areas volumes misc

12-31-2007

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17:30:09

`questionNumber 20000

`q001. There are 9 questions and 4 summary questions in this assignment.

What is the volume of a rectangular solid whose dimensions are exactly 3 cm by 5 cm by 7 cm?

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RESPONSE -->

105

confidence assessment: 3

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17:31:29

`questionNumber 20000

`q002. What is the volume of a rectangular solid whose base area is 48 square meters and whose altitude is 2 meters?

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RESPONSE -->

96

confidence assessment: 2

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17:33:41

`questionNumber 20000

`q003. What is the volume of a uniform cylinder whose base area is 20 square meters and whose altitude is 40 meters?

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RESPONSE -->

16000 pi

confidence assessment: 2

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????????y???`??

assignment #001

001. Rates

qa rates

01-01-2008

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10:13:55

`questionNumber 10000

`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 -->

$10 an hr

confidence assessment: 2

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10:16:47

`questionNumber 10000

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

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RESPONSE -->

$5000

confidence assessment: 3

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10:17:33

`questionNumber 10000

`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 -->

an average of $5000 per month

confidence assessment: 2

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10:22:21

`questionNumber 10000

`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. unsure of 2nd part of question

confidence assessment: 2

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10:23:34

`questionNumber 10000

`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 -->

20

confidence assessment: 2

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10:24:45

`questionNumber 10000

`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 -->

confidence assessment: 0

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10:26:21

`questionNumber 10000

`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 -->

confidence assessment: 0

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10:27:57

`questionNumber 10000

`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 -->

confidence assessment: 0

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10:29:16

`questionNumber 10000

`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 -->

10

confidence assessment: 2

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10:30:35

`questionNumber 10000

`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 -->

2.2

confidence assessment: 1

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10:31:18

`questionNumber 10000

`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 -->

confidence assessment: 0

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??|???????????V?assignment #006

006. Physics

qa initial problems

01-01-2008

??`?????????assignment #002

002. Describing Graphs

qa initial problems

01-01-2008

?????|x??d??????assignment #002

002. Describing Graphs

qa initial problems

01-01-2008

???????z???assignment #002

002. Describing Graphs

qa initial problems

01-01-2008

??????n??????

assignment #002

002. Describing Graphs

qa initial problems

01-02-2008

????w???X???

assignment #005

005. Calculus

qa initial problems

01-02-2008

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21:06:29

`questionNumber 50000

`q001. The graph of a certain function is a smooth curve passing through the points (3, 5), (7, 17) and (10, 29).

Between which two points do you think the graph is steeper, on the average?

Why do we say 'on the average'?

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RESPONSE -->

average is not an exact number. but more of an approximation

confidence assessment: 3

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?d????b?a????

assignment #002

002. Velocity

Physics I

01-27-2008

b??????|???

assignment #002

002. Velocity

Physics I

01-28-2008

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19:03:57

`questionNumber 20000

`q001. Note that there are 14 questions in this assignment.

If an object moves 12 meters in 4 seconds, then at what average rate is the object moving? Explain how you obtained your result in terms of commonsense images.

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RESPONSE -->

average rate would be 3.

distance/ time gives you the rate

confidence assessment: 3

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19:07:39

`questionNumber 20000

`q002. How is this problem related to the concept of a rate?

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RESPONSE -->

it represents the relationship between distance and time

confidence assessment: 3

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19:19:13

`questionNumber 20000

`q003. Is object position dependent on time or is time dependent on object position?

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RESPONSE -->

object position is dependent on time

confidence assessment: 2

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19:24:15

`questionNumber 20000

`q004. So the rate here is the average rate at which position is changing with respect to clock time. Explain what concepts, if any, you missed in your explanations.

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RESPONSE -->

whether the object is moving or not, time would still continue and is not dependent on position

confidence assessment: 3

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19:29:28

`questionNumber 20000

`q005. If an object is displaced -6 meters in three seconds, then what is the average speed of the object what is its average velocity? Explain how you obtained your result in terms of commonsense images and ideas.

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RESPONSE -->

-2 would be the average speed. distance over time. average velocity would be the same.

confidence assessment: 2

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19:30:37

`questionNumber 20000

Speed is the average rate at which distance changes, and distance cannot be negative. Therefore speed cannot be negative. Velocity is the average rate at which position changes, and position changes can be positive or negative.

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RESPONSE -->

didnt know that in determining average speed, distance cannot be negative.

self critique assessment: 2

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21:15:21

`questionNumber 20000

`q006. If `ds stands for the change in the position of an object and `dt for the time interval during which the position changes, then what expression stands for the average velocity vAve of the object during this time interval?

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RESPONSE -->

dv

confidence assessment: 3

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21:16:36

`questionNumber 20000

Average velocity is rate of change of position. Change in position is `ds and change in clock tim is `dt, so vAve = `ds / `dt.

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RESPONSE -->

misunderstood the question. i thought it was asking what average velocity would be in the formula

self critique assessment: 2

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21:18:20

`questionNumber 20000

`q007. How do you write the expressions `ds and `dt on your paper?

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RESPONSE -->

v=ds/dt

confidence assessment: 3

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21:19:56

`questionNumber 20000

`q008. If an object changes position at an average rate of 5 meters/second for 10 seconds, then how far does it move?

How is this problem related to the concept of a rate?

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RESPONSE -->

again it shows the relationship between distance and time. 5/10 =2 which is the average rate

confidence assessment: 3

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21:24:53

`questionNumber 20000

`q009. If vAve stands for the rate at which the position of the object changes (also called velocity) and `dt for the time interval during which the change in position is to be calculated, then how to we write the expression for the change `ds in the position?

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RESPONSE -->

vave=dt/ds

confidence assessment: 2

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21:25:34

`questionNumber 20000

To find the change in a quantity we multiply the rate by the time interval during which the change occurs. We therefore obtain the change in position by multiplying the velocity by the time interval: `ds = vAve * `dt. The units of this calculation pretty much tell us what to do: Just as when we multiply pay rate by time (dollar / hr * hours of work) or automobile velocity by the time interval (miles / hour * hour), when we multiply vAve, in cm / sec or meters / sec or whatever, by `dt in seconds, we get displacement in cm or meters, or whatever, depending on the units of distance used.

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RESPONSE -->

was unsure with this one

self critique assessment: 1

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21:28:21

`questionNumber 20000

`q010. Explain how the quantities average velocity vAve, time interval `dt and displacement `ds are related by the definition of a rate, and how this relationship can be used to solve the current problem problem.

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RESPONSE -->

average velocity is between 2 times. the distance of an object and the elapsed time.

confidence assessment: 2

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21:37:25

`questionNumber 20000

`q011. The basic rate relationship vAve = `ds / `dt expresses the definition of average velocity vAve as the rate at which position s changes with respect to clock time t. What algebraic steps do we use to solve this equation for `ds, and what is our result?

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RESPONSE -->

vAve*dt=ds

confidence assessment: 2

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21:41:16

`questionNumber 20000

`q012. How is this result related to our intuition about the meanings of the terms average velocity, displacement and clock time?

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RESPONSE -->

the average velocity moves through the displacement and then through the clocked time.

confidence assessment: 2

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21:42:38

`questionNumber 20000

`q013. What algebraic steps do we use to solve the equation vAve = `ds / `dt for `dt, and what is our result?

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RESPONSE -->

ds/vAve=dt

confidence assessment: 2

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21:43:28

`questionNumber 20000

To solve vAve = `ds / `dt for `dt, we must get `dt out of the denominator. Thus we first multiply both sides by the denominator `dt. Then we can see where we are and takes the appropriate next that. The steps:

vAve = `ds / `dt. Multiply both sides by `dt:

vAve * `dt = `ds / `dt * `dt Since `dt / `dt = 1

vAve * `dt = `ds. We can now divide both sides by vAve to get `dt = `ds / vAve.

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RESPONSE -->

i need to remember to write out the steps in any problem . not just the answer

self critique assessment: 2

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21:47:45

`questionNumber 20000

`q014. How is this result related to our intuition about the meanings of the terms average velocity, displacement and clock time?

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RESPONSE -->

displacement of an object through the velocity of the object gives the clocked time of the object

confidence assessment: 2

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?vZ??????????

assignment #003

003. Velocity Relationships

Physics I

01-30-2008

?????????????

assignment #003

003. Velocity Relationships

Physics I

01-30-2008

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20:04:44

`questionNumber 30000

`q001. Note that there are 11 questions in this assignment.

vAve = `ds / `dt, which is the definition of average velocity and which fits well with our intuition about this concept. If displacement `ds is measured in meters and the time interval `dt is measured in seconds, in what units will vAve be obtained?

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RESPONSE -->

vAve= m/seconds

confidence assessment: 3

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20:05:28

`questionNumber 30000

vAve = `ds / `dt. The units of `ds are cm and the units of `dt are sec, so the units of `ds / `dt must be cm / sec. Thus vAve is in cm/s.

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RESPONSE -->

i thought the question stated meters not cm

self critique assessment: 2

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20:18:48

`questionNumber 30000

`q002. If the definition equation vAve = `ds / `dt is to be solved for `ds we multiply both sides of the equation by `dt to obtain `ds = vAve * `dt. If vAve is measured in cm / sec and `dt in sec, then in what units must `ds be measured?

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RESPONSE -->

cm

confidence assessment: 3

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20:23:19

`questionNumber 30000

`q003. Explain the algebra of multiplying the unit cm / sec by the unit sec.

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RESPONSE -->

vAve*dt=ds

cm/sec is multiplied by seconds which would give the answer with the unit cm

confidence assessment: 3

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20:23:58

`questionNumber 30000

`q004. If the definition vAve = `ds / `dt is to be solved for `dt we multiply both sides of the equation by `dt to obtain vAve * `dt = `ds, then divide both sides by vAve to get `dt = `ds / vAve. If vAve is measured in km / sec and `ds in km, then in what units must `dt be measured?

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RESPONSE -->

dt would be measured in seconds

confidence assessment: 3

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20:25:20

`questionNumber 30000

`q005. Explain the algebra of dividing the unit km / sec into the unit km.

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RESPONSE -->

dt=ds/vAve

km is multiplied and then divided by km/sec to give the answer dt in the unit seconds

confidence assessment: 3

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20:26:14

`questionNumber 30000

`q006. If an object moves from position s = 4 meters to position s = 10 meters between clock times t = 2 seconds and t = 5 seconds, then at what average rate is the position of the object changing (i.e., what is the average velocity of the object) during this time interval? What is the change `ds in position, what is the change `dt in clock time, and how do we combine these quantities to obtain the average velocity?

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RESPONSE -->

forgot to mention the division of km/sec

confidence assessment:

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?????????~????assignment #003

003. Velocity Relationships

Physics I

01-30-2008

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20:28:28

`questionNumber 30000

`q005. Explain the algebra of dividing the unit km / sec into the unit km.

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RESPONSE -->

confidence assessment: 0

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20:29:03

`questionNumber 30000

The division is km / (km / sec). Since division by a fraction is multiplication by the reciprocal of the fraction, we have km * (sec / km). This is equivalent to multiplication of fractions (km / 1) * (sec / km). Multiplying numerators and denominators we get (km * sec) / (1 * km), which can be rearranged to give us (km / km) * (sec / 1), or 1 * sec / 1, or just sec.

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RESPONSE -->

forgot to mention the division of km/sec the first time

self critique assessment: 2

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20:33:22

`questionNumber 30000

`q006. If an object moves from position s = 4 meters to position s = 10 meters between clock times t = 2 seconds and t = 5 seconds, then at what average rate is the position of the object changing (i.e., what is the average velocity of the object) during this time interval? What is the change `ds in position, what is the change `dt in clock time, and how do we combine these quantities to obtain the average velocity?

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RESPONSE -->

10-4=6 meters

5-2=3 seconds

6meters/3seconds would be 2 m/sec. even if the measurements were added, the answer would be the same.

confidence assessment: 3

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20:35:32

`questionNumber 30000

`q007. Symbolize this process: If an object moves from position s = s1 to position s = s2 between clock times t = t1 and t = t2, when what expression represents the change `ds in position and what expression represents the change `dt in the clock time?

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RESPONSE -->

s2-s1=s1

t2-t1=t1

position(s1)/clock time(t1)

confidence assessment: 2

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20:36:41

`questionNumber 30000

We see that the change in position is `ds = s2 - s1, obtained as usual by subtracting the first position from the second. Similarly the change in clock time is `dt = t2 - t1. What expression therefore symbolizes the average velocity between the two clock times.

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RESPONSE -->

s1/t1=1vAve

self critique assessment: 3

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20:53:00

`questionNumber 30000

`q008. On a graph of position s vs. clock time t we see that the first position s = 4 meters occurs at clock time t = 2 seconds, which corresponds to the point (2 sec, 4 meters) on the graph, while the second position s = 10 meters occurs at clock time t = 5 seconds and therefore corresponds to the point (5 sec, 10 meters). If a right triangle is drawn between these points on the graph, with the sides of the triangle parallel to the s and t axes, the rise of the triangle is the quantity represented by its vertical side and the run is the quantity represented by its horizontal side. This slope of the triangle is defined as the ratio rise / run. What is the rise of the triangle (i.e., the length of the vertical side) and what quantity does the rise represent? What is the run of the triangle and what does it represent?

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RESPONSE -->

a=1/2*b*h

5=1/2*(10)*h

2=h

h=2. so this would be the lenght of the vertical side of the triangle. the rise represents seconds.

b*h

10*2=20. the run of the triangle is 20. and it represents meters

confidence assessment: 2

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20:54:04

`questionNumber 30000

The rise of the triangle represents the change in the position coordinate, which from the first point to the second is 10 m - 4 m = 6 m. The run of the triangle represents the change in the clock time coordinate, which is 5 s - 2 s = 3 s.

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RESPONSE -->

was way off with this one.

self critique assessment: 1

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???????????|

assignment #003

003. Velocity Relationships

Physics I

01-30-2008

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21:02:15

`questionNumber 30000

`q009. What is the slope of this triangle and what does it represent?

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RESPONSE -->

rise/run of the slope

6m/3sec would give you 2m/sec

confidence assessment: 3

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21:10:41

`questionNumber 30000

`q010. In what sense does the slope of any graph of position vs. clock time represent the velocity of the object? For example, why does a greater slope imply greater velocity?

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RESPONSE -->

by dividing the the position of the object by time would give the vAve.

confidence assessment: 3

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21:14:15

`questionNumber 30000

`q011. As a car rolls from rest down a hill, its velocity increases. Describe a graph of the position of the car vs. clock time.

If you have not already done so, tell whether the graph is increasing at an increasing rate, increasing at a decreasing rate, decreasing at an increasing rate, decreasing at a decreasing rate, increasing at a constant rate or decreasing at a constant rate.

Is the slope of your graph increasing or decreasing?

How does the behavior of the slope of your graph indicate the condition of the problem, namely that the velocity is increasing?

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RESPONSE -->

velocity would be increasing at a decreasing rate. so from the veritcal side of the graph, it would slowly curve downards as it decreases

confidence assessment: 2

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