#$&*
Phy 201
Your 'cq_1_16.1' report has been received. Scroll down through the document to see any comments I might have inserted, and my final comment at the end.
** **
Seed Question 16-1
The purpose and the process of answering 'seed' questions:
In cloud seeding small crystalline particles (the 'seeds') are scattered throughout a cloud, so that water vapor in the cloud will build up on the 'seed' and eventually fall in the form of rain.
These questions are posed without any previous explanation. You are expected to use what you already know, along with common sense, to answer the questions. It is standard practice in many courses to an instructor to give explanations and examples before asking students to answer questions, and you will see plenty of examples and explanations in this course. However the goal here is to first experience and think about a situation. Whether you think correctly or incorrectly, your thinking gets you started on an idea and forms a 'seed' on which understanding can accumulate.
You are expected to answer it to the best of your ability, based on what you know at the beginning of this assignment.
You are not expected to research this question until after you have submitted your best response.
You are not penalized based on whether your answer is 'right' or 'wrong', but you are expected to think as clearly and deeply as you can about the question.
You are not, however, expected to spend hours thinking about the question or agonize unduly about your answers. A rule of thumb is to give it up to 20 minutes, half for thinking and half for typing in your answers (maybe a little more for the typing if you don't have good keyboard skills).
Your answers should consist of your best attempt at a solution, and/or one or more questions about the situation.
If you think you know the answer or can make a reasonable attempt to answer, then give your answer along with a concise outline of your reasoning.
If you aren't sure what the question is asking, make your best attempt to interpret and answer it, and consider including one or more questions.
If you are very sure you don't know what the question is asking, then break it down phrase-by-phrase or even word-by-word and explain what you think each key phrase or word might mean.
A question consists of a complete but concise statement of what you do and do not understand about the situation.
There are two ways you can spend an excessive amount of time explaining your solutions and/or asking questions. One is to type a lot more than what is necessary, and another is to spend a lot of time worrying about what is and is not necessary. Balance the two in the way that works best for you.
Remember that the 'concise' part is more for your benefit than mine. I can read a lot more quickly than you can type, and don't mind reading through a lot of words to understand your meaning.
You are invited but not required to include comments and/or discussion.
You are welcome to use reasonable abbreviations in your work.
________________________________________
Copy the problem below into a text editor or word processor.
This form accepts only text so a text editor such as Notepad is fine.
You might prefer for your own reasons to use a word processor (for example the formatting features might help you organize your answer and explanations), but note that formatting will be lost when you submit your work through the form.
If you use a word processor avoid using special characters or symbols, which would require more of your time to create and will not be represented correctly by the form.
As you will see within the first few assignments, there is an easily-learned keyboard-based shorthand that doesn't look quite as pretty as word-processor symbols, but which gets the job done much more efficiently.
You should enter your answers using the text editor or word processor. You will then copy-and-paste it into the box below, and submit.
________________________________________
A rubber band has no tension until it reaches a length of 7.5 cm. Beyond that length its tension increases by .7 Newtons for every additional centimeter of length.
What will be its tension if its endpoints are at the points (5 cm, 9 cm) and (10 cm, 17 cm) as measured on an x-y coordinate system?
answer/question/discussion: ->->->->->->->->->->->-> :
Are the endpoints the actual length of the rubber band or the endpoints of the rubber band?
If the endpoints are the actual endpoints of the rubber band then the coordinates would both be (0,0) because the rubber band never reaches 7.5 cm.
So I am going to assume the endpoints are the total length of the rubber band.
(0, 1.05) (1.75, 6.65)
#$&*
What is the vector from the first point to the second?
answer/question/discussion: ->->->->->->->->->->->-> :
I dont know exactly what you are asking for, but maybe the difference between the two points?
1.75, 5.60
#$&*
What is the magnitude of this vector?
answer/question/discussion: ->->->->->->->->->->->-> :
I have no idea. I obviously have very little understanding of the meaning of a vector and how to find it. My basic understanding is that a vector is a straight line, but thats about it. It doesnt make much sense to answer the rest of these questions right now because I cant follow what you mean.
#$&*
What vector do you get when you divide this vector by its magnitude? (Specify the x and y components of the resulting vector).
answer/question/discussion: ->->->->->->->->->->->-> :
#$&*
The new vector should have magnitude 1. When you divide a vector by its magnitude the result is a vector with magnitude 1. We call a vector of magnitude 1 a unit vector. What vector do you get when you multiply this new vector (i.e., the unit vector) by the tension?
answer/question/discussion: ->->->->->->->->->->->-> :
#$&*
What are the x and y components of the new vector?
answer/question/discussion: ->->->->->->->->->->->-> :
#$&*
This new vector is called the tension vector. It is a force vector which represents the tension. A force vector can be specified by its components, or equivalently by its magnitude and direction.
** **
5 minutes
** **
4/9/13 1111am
self-critique rating
#$&*
Phy 201
Your 'cq_1_16.1' report has been received. Scroll down through the document to see any comments I might have inserted, and my final comment at the end.
** **
Seed Question 16-1
The purpose and the process of answering 'seed' questions:
In cloud seeding small crystalline particles (the 'seeds') are scattered throughout a cloud, so that water vapor in the cloud will build up on the 'seed' and eventually fall in the form of rain.
These questions are posed without any previous explanation. You are expected to use what you already know, along with common sense, to answer the questions. It is standard practice in many courses to an instructor to give explanations and examples before asking students to answer questions, and you will see plenty of examples and explanations in this course. However the goal here is to first experience and think about a situation. Whether you think correctly or incorrectly, your thinking gets you started on an idea and forms a 'seed' on which understanding can accumulate.
You are expected to answer it to the best of your ability, based on what you know at the beginning of this assignment.
You are not expected to research this question until after you have submitted your best response.
You are not penalized based on whether your answer is 'right' or 'wrong', but you are expected to think as clearly and deeply as you can about the question.
You are not, however, expected to spend hours thinking about the question or agonize unduly about your answers. A rule of thumb is to give it up to 20 minutes, half for thinking and half for typing in your answers (maybe a little more for the typing if you don't have good keyboard skills).
Your answers should consist of your best attempt at a solution, and/or one or more questions about the situation.
If you think you know the answer or can make a reasonable attempt to answer, then give your answer along with a concise outline of your reasoning.
If you aren't sure what the question is asking, make your best attempt to interpret and answer it, and consider including one or more questions.
If you are very sure you don't know what the question is asking, then break it down phrase-by-phrase or even word-by-word and explain what you think each key phrase or word might mean.
A question consists of a complete but concise statement of what you do and do not understand about the situation.
There are two ways you can spend an excessive amount of time explaining your solutions and/or asking questions. One is to type a lot more than what is necessary, and another is to spend a lot of time worrying about what is and is not necessary. Balance the two in the way that works best for you.
Remember that the 'concise' part is more for your benefit than mine. I can read a lot more quickly than you can type, and don't mind reading through a lot of words to understand your meaning.
You are invited but not required to include comments and/or discussion.
You are welcome to use reasonable abbreviations in your work.
________________________________________
Copy the problem below into a text editor or word processor.
This form accepts only text so a text editor such as Notepad is fine.
You might prefer for your own reasons to use a word processor (for example the formatting features might help you organize your answer and explanations), but note that formatting will be lost when you submit your work through the form.
If you use a word processor avoid using special characters or symbols, which would require more of your time to create and will not be represented correctly by the form.
As you will see within the first few assignments, there is an easily-learned keyboard-based shorthand that doesn't look quite as pretty as word-processor symbols, but which gets the job done much more efficiently.
You should enter your answers using the text editor or word processor. You will then copy-and-paste it into the box below, and submit.
________________________________________
A rubber band has no tension until it reaches a length of 7.5 cm. Beyond that length its tension increases by .7 Newtons for every additional centimeter of length.
What will be its tension if its endpoints are at the points (5 cm, 9 cm) and (10 cm, 17 cm) as measured on an x-y coordinate system?
answer/question/discussion: ->->->->->->->->->->->-> :
Are the endpoints the actual length of the rubber band or the endpoints of the rubber band?
If the endpoints are the actual endpoints of the rubber band then the coordinates would both be (0,0) because the rubber band never reaches 7.5 cm.
So I am going to assume the endpoints are the total length of the rubber band.
(0, 1.05) (1.75, 6.65)
@&
(5 cm, 9 cm) and (10 cm, 17 cm) are points on an xy coordinate system, and the ends of the rubber band are at these points.
From the coordinates of its endpoints you can find the length of the rubber band.
*@
#$&*
What is the vector from the first point to the second?
answer/question/discussion: ->->->->->->->->->->->-> :
I dont know exactly what you are asking for, but maybe the difference between the two points?
1.75, 5.60
#$&*
What is the magnitude of this vector?
answer/question/discussion: ->->->->->->->->->->->-> :
I have no idea. I obviously have very little understanding of the meaning of a vector and how to find it. My basic understanding is that a vector is a straight line, but thats about it. It doesnt make much sense to answer the rest of these questions right now because I cant follow what you mean.
#$&*
What vector do you get when you divide this vector by its magnitude? (Specify the x and y components of the resulting vector).
answer/question/discussion: ->->->->->->->->->->->-> :
#$&*
The new vector should have magnitude 1. When you divide a vector by its magnitude the result is a vector with magnitude 1. We call a vector of magnitude 1 a unit vector. What vector do you get when you multiply this new vector (i.e., the unit vector) by the tension?
answer/question/discussion: ->->->->->->->->->->->-> :
#$&*
What are the x and y components of the new vector?
answer/question/discussion: ->->->->->->->->->->->-> :
#$&*
This new vector is called the tension vector. It is a force vector which represents the tension. A force vector can be specified by its components, or equivalently by its magnitude and direction.
** **
5 minutes
** **
@&
Vectors are a standard topic in the mathematics courses prerequisite to this one, but the majority of students appear to get through those courses without any significant work with vectors, so I don't assume them. I introduce them in Introductory Problem Set 5, which you should review, and in the Class Notes.
A vector is any quantity that has a magnitude and a direction.
The displacement vector from the first point to the second can be thought of as an arrow from the first point to the second.
If you were to draw that arrow, how long would it be? The answer to this question is the magnitude of the displacement vector.
What angle would the displacement vector make with the positive x direction? By specifying this angle you have specified the direction of the vector.
At this point the first five problems from the Introductory Problem Sets have been assigned. Between my notes and the information contained in those problem sets, you should be able to make a good attempt at answering my questions, and you may well be able to then answer the remaining questions in this problem.
Give yourself a reasonable but not exhorbitant amount of time then submit your best attempt (and/or questions for clarification). We'll go from there.
*@