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: ->->->->->->->->->->->-> : Quantity A is the cm measurement. Quantity B is the time measurement. 10/5= 2cm/s avg rate
&#Units should be represented in every step of every calculation, and should be treated as algebraic symbols to be combined and simplified according to the rules of algebra. An error in the units of your final quantity can indicate a flaw in your sequence of calculations; this could also reveal an algebraic errors with the units, which should be corrected. &#
• 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: ->->->->->->->->->->->-> : Quant. A is the velocity. Quantity B is the clock change time. 30/3 = 10 cm/s
• 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: ->->->->->->->->->->->-> : Quant. A is the 5 cm/s and quant. B is the 10 second interval. To solve this you multiply A and B, to give a 50 cm change in position.
• 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: ->->->->->->->->->->->-> : I will study and memorize the definition of the rate of change of one quantity with respect to another.
• 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: ->->->->->->->->->->->-> : To apply this definition you take a change in a quantity A and divide it by a change in a quantity B. I will remember by studying and practice.
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10 minutes.
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Good. You understand how to apply the definitions and did so correctly. You did make at least one error in units and your wording related to the definition wasn't always completely precise, so be sure to see the discussion at the link below. However unless you have questions you don't need to submit any revisions:
&#Please compare your solutions with the expanded discussion at the link
Solution
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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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ph1 query 1
Question: `qExplain in your own words how the standard deviation of a set of numbers is calculated.
Your solution: To calculate the standard deviation, we must first have the mean of the entire data set. After that, we can then examine a smaller set of data within the whole set. Let’s say we have 6 data points to examine. We compare the mean time of the whole set compared to the 6 individual points. The difference in the mean of the set and the data points is called the deviation. The next step to get the standard deviation is to get a sum of the squares of the deviations. Next we must divide this sum by # of data points-1. The final step is to take the square root of this number. This is the standard deviation.
Confidence Assessment: 3
Question: Explain in your own words the process of fitting a straight line to a graph of y vs. x data, and briefly discuss the nature of the uncertainties encountered in the process. For example, you might address the question of how two different people, given the same graph, might obtain different results for the slope and the vertical intercept.
Your solution: The process of fitting a straight line to a graph of y vs. x data is to get the line closest to the average of the points. This is to say that the line should try to AVOID the data points and go between them to get an average. Different people may estimate differently since the process isn’t a definite one. Most likely no one will have the exact same answer from guessing.
Confidence Assessment: 3
Question: Briefly state what you think velocity is and how you think it is an example of a rate.
Your solution: A rate can be described as a change in quantity a divided by the change in quantity b. Velocity can best be described as a rate of change, such as the change in distance with respect to time. The distance is measured vs. the time it took the object to get to that distance.
Confidence Assessment: 3
Given Solution:
A rate is a change in something divided by a change in something else.
This question concerns velocity, which is the rate of change of position: change in position divided by change in clock time. **
Self-critique (if necessary): ok
Question: Given average speed and time interval how do you find distance moved?
Your solution: To find the distance moved from the speed and time you multiply the average speed by the distance moved. This will cancel out the unit of time and leave you with the distance moved.
Confidence Assessment: 3
Given Solution:
** You multiply average speed * time interval to find distance moved.
For example, 50 miles / hour * 3 hours = 150 miles. **
Self-critique (if necessary):ok
Question: Given average speed and distance moved how do you find the corresponding time interval?
Your solution: You divide the distance moved by the rate to get the time interval.
Confidence Assessment: 3
Given Solution:
** time interval = distance / average speed. For example if we travel 100 miles at 50 mph it takes 2 hours--we divide the distance by the speed.
In symbols, if `ds = vAve * `dt then `dt = `ds/vAve.
Also note that (cm/s ) / s = cm/s^2, not sec, whereas cm / (cm/s) = cm * s / cm = s, as appropriate in a calculation of `dt. **
Self-critique (if necessary): ok
Question: Given time interval and distance moved how do you get average speed?
Your solution: To get the avg speed you take the distance divided by the change in time.
Confidence Assessment: ok
Given Solution:
** Average speed = distance / change in clock time. This is the definition of average speed.
For example if we travel 300 miles in 5 hours we have been traveling at an average speed of 300 miles / 5 hours = 60 miles / hour. **
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20 minutes
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Very good, but this should have been submitted using the Submit Work Form, not the form for the cq_ problem. No need to resubmit, but to ensure proper format in the posted documents use the appropriate forms.