course Phy 121 ÖmûÔÜósŸÏoÉÐÞº`…¨è~¹¦·÷¯Ë©assignment #000
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11:49:38 The Query program normally asks you questions about assigned problems and class notes, in question-answer-self-critique format. Since Assignments 0 and 1 consist mostly of lab-related activities, most of the questions on these queries will be related to your labs and will be in open-ended in form, without given solutions, and will not require self-critique. The purpose of this Query is to gauge your understanding of some basic ideas about motion and timing, and some procedures to be used throughout the course in analyzing our observations. Answer these questions to the best of your ability. If you encounter difficulties, the instructor's response to this first Query will be designed to help you clarify anything you don't understand. {}{}Respond by stating the purpose of this first Query, as you currently understand it.
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RESPONSE --> Because assignment 0 is mostly lab related, answers will be open ended with no specific answer given. This query is meant to determine my knowledge of motion, timing, and my observations.
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11:51:22 If, as in the object-down-an-incline experiment, you know the distance an object rolls down an incline and the time required, explain how you will use this information to find the object 's average speed on the incline.
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RESPONSE --> By dividing the distance traveled by the time it took for the object, you can find the average speed. confidence assessment: 2
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11:54:44 If an object travels 40 centimeters down an incline in 5 seconds then what is its average velocity on the incline? Explain how your answer is connected to your experience.
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RESPONSE --> By dividing 40 cm by 5 seconds, I found the average velocity of 8 cm/second. This is connected to my experience because I used the same method to find the average speed in my experiment. confidence assessment: 2
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12:36:20 If the same object requires 3 second to reach the halfway point, what is its average velocity on the first half of the incline and what is its average velocity on the second half?
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RESPONSE --> By dividing 20 cm by 3 seconds, I found the average velocity for the first half is 6.67 cm/second. And by dividing 20 cm by 2 seconds, I found the average velocity for the second half is 10 cm/second. confidence assessment: 3
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12:55:32 Using the same type of setup you used for the first object-down-an-incline lab, if the computer timer indicates that on five trials the times of an object down an incline are 2.42 sec, 2.56 sec, 2.38 sec, 2.47 sec and 2.31 sec, then to what extent do you think the discrepancies could be explained by each of thefollowing: {}{}a. The lack of precision of the TIMER program{}{}b. The uncertain precision of human triggering (uncertainty associated with an actual human finger on a computer mouse){}{}c. Actual differences in the time required for the object to travel the same distance.{}{}d. Differences in positioningthe object prior to release.{}{}e. Human uncertainty in observing exactly when the object reached the end of the incline.
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RESPONSE --> a. I think this has the least to do with the differences in the times, because the TIMER program is very accurate. b. This could affect the time measures because the person may stop the timer too soon or too late. c. Differences in the time the object needs to travel could be caused if the object does not move down the incline on the same path, or if the person influences the objects speed by pushing it. d. Different times would be found if the object is not positioned the same way each time, because the angle it travels on would affect the time the object needs to move down the incline. e. Because it is difficult to know exactly when the object reaches the end of the incline, this will cause the timer to stop too soon or too late. confidence assessment: 2
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13:31:08 How much uncertainty do you think each of the following would actually contribute to the uncertainty in timing a number of trials for the object-down-an-incline lab? {}{}a. The lack of precision of the TIMER program{}{}b. The uncertain precision of human triggering (uncertainty associated bLine$(lineCount) =with an actual human finger on a computer mouse){}{}c. Actual differences in the time required for the object to travel the same distance.{}{}d. Differences in positioning the object prior to release.{}{}e. Human uncertainty in observing exactly when the object reached the end of the incline.
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RESPONSE --> a. This would cause the least uncertainty as the TIMER is accurate to .01 seconds. b. This would cause fractions of a second in the uncertainty because the person could stop the timer either to early or too late. c. This should not cause much uncertainty, because the object should travel the distance in the same time if the object is always has the same velocity. d. Because differences in positioning the object at the top of the incline will cause the object to travel down the incline in different patterns, this will cause the second most amount of uncertainty in the experiment. e. It is difficult to know exactly when the object reaches the end of the incline and this will cause the most uncertainty in timing the object. confidence assessment: 2
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13:40:22 What, if anything, could you do about the uncertainty due to each of the following? Address each specifically. {}{}a. The lack of precision of the TIMER program{}{}b. The uncertain precision of human triggering (uncertainty associated with an actual human finger on a computer mouse){}{}c. Actualdifferences in the time required for the object to travel the same distance.{}{}d. Differences in positioning the object prior to release.{}{}e. Human uncertainty in observing exactly when the object reached the end of the incline.
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RESPONSE --> a. You cannot change the precision of the TIMER. b. There is little you can do for the triggering for stopping the TIMER other than making sure you click consistently and accurately. c. By contolling the angle of the incline, you can control the time which the object travels. d. By making sure the object stays in the same position for each trial, you can greatly reduce uncertainty in the results. e. Uncertainty can be minimized if you carefully observe when the object reaches the end and stop the TIMER at the right time. confidence assessment: 3
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13:49:22 According to the results of your introductory pendulum experiment, do you think doubling the length of the pendulum will result in half the frequency (frequency can be thought of as the number of cycles per minute), more than half or less than half?
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RESPONSE --> I think doubling the length of the pendulum will result in less than half the frequency. confidence assessment: 2
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13:54:08 Note that for a graph of y vs. x, a point on the x axis has y coordinate zero and a point on the y axis has x coordinate zero. In your own words explain why this is so.
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RESPONSE --> Because if a point is on the y-axis, the x coordinate can only = 0 and cannot be changed if the point stays on the y-axis only, because the point cannot move left or right.. The same reason is applied if the point is on the x-axis, then the y coordinate must be zero and cannot be changed if the point stays on the x-axis, because the point cannot move up or down the y-axis. confidence assessment: 2
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14:00:04 On a graph of frequency vs. pendulum length (where frequency is on the vertical axis and length on the horizontal), what would it mean for the graph to intersect the vertical axis (i.e., what would it mean, in terms of the pendulum and its behavior, if the line or curve representing frequency vs. length goes through the vertical axis)? What would this tell you about the length and frequency of the pendulum?
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RESPONSE --> If the graph intersected the the vertical axis, then that would mean the length of the pendulum is negative. confidence assessment: 0
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14:01:14 On a graph of frequency vs. pendulum length, what would it mean for the graph to intersect the horizontal axis (i.e., what would it mean, in terms of the pendulum and its behavior, if the line or curve representing frequency vs. length goes through the horizontal axis)? What would this tell you about the length and frequency of the pendulum?
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RESPONSE --> If the graph would intersect the horizontal axis, then that would mean the frequency is a negative value. confidence assessment: 0
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14:02:39 If a ball rolls down between two points with an average velocity of 6 cm / sec, and if it takes 5 sec between the points, then how far apart are the points?
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RESPONSE --> 5 sec * 6 cm = distance of 30 cm if it is traveling at a rate of 6cm/sec confidence assessment: 3
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14:02:53 On the average the ball moves 6 centimeters every second, so in 5 seconds it will move 30 cm. {}{}The formal calculation goes like this: {}{}We know that vAve = `ds / `dt, where vAve is ave velocity, `ds is displacement and `dt is the time interval. {}It follows by algebraic rearrangement that `ds = vAve * `dt.{}We are told that vAve = 6 cm / sec and `dt = 5 sec. It therefore follows that{}{}`ds = 6 cm / sec * 5 sec = 30 (cm / sec) * sec = 30 cm.{}{}The details of the algebraic rearrangement are asfollows:{}{}vAve = `ds / `dt. We multiply both sides of the equation by `dt:{}vAve * `dt = `ds / `dt * `dt. We simplify to obtain{}vAve * `dt = `ds, which we then write as{}`ds = vAve *`dt.{}{}Be sure to address anything you do not fully understand in your self-critique.
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RESPONSE --> ok self critique assessment: 3
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14:11:59 You were asked to read the text and some of the problems at the end of the section. Tell me about something in the text you understood up to a point but didn't understand fully. Explain what you did understand, and ask the best question you can about what you didn't understand.
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RESPONSE --> I understood most things in this chapter up to a point, such as how to meaure uncertainty in measurements and systems of units. One thing that confused me was how the differences between the definitions of ""laws"" and ""principles"" was explained in the text. confidence assessment: 3
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14:22:01 Tell me about something in the problems you understand up to a point but don't fully understand. Explain what you did understand, and ask the best question you can about what you didn't understand.
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RESPONSE --> I was not sure how to do problem #12, where the numbers had to be written as full decimal numbers with standard units. confidence assessment: 3
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