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Phy 201
Your 'cq_1_17.2' 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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Seed Question 17-2
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.
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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.
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A 5 kg cart rests on an incline which makes an angle of 30 degrees with the horizontal.
Sketch this situation with the incline rising as you move to the right and the cart on the incline. Include an x-y coordinate system with the origin centered on the cart, with the x axis directed up and to the right in the direction parallel to the incline.
The gravitational force on the cart acts vertically downward, and therefore has nonzero components parallel and perpendicular to the incline.
Sketch the x and y components of the force, as estimate the magnitude of each component.
What angle does the gravitational force make with the positive x axis, as measured counterclockwise from the positive x axis? Which is greater in magnitude, the x or the y component of the gravitational force?
answer/question/discussion: ->->->->->->->->->->->-> :
The angle of the gravitational force and the x axis (if I understood the directions) is 150 degrees. I still dont follow how to know which is greater in magnitude, the x or y component of the gravitational force. Just a guess but I would say the x component is greater in magnitude.
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Is a vector at 150 degrees closer to the x or the y axis?
If you project the vector onto the x axis and onto the y axis (i.e., sketch a dotted line from the end of the vector to each axis, with the dotted line parallel to the other axis), which projection is longer?
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Using the definitions of the sine and cosine, find the components of the cart's weight parallel and perpendicular to the incline.
answer/question/discussion: ->->->->->->->->->->->-> :
It has been way too long since I have used any form of trigonometry. I dont have any idea about the definition of sine or cosine. Doing a quick internet search, sin= opposite /hypotenuse and cosin= adjacent /hypotenuse. This seems vaguely familiar but I cant apply these definitions into anything meaningful for this question.
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Most students don't remember much trigonometry. That is the reason for Introductory Problem Set 5, which provides you with enough trigonometry to do the work in this course.
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The formulas given in Introductory Problem Set 5 are sufficient to obtain this result. Review that assignment, let me know if you have questions, then give this problem another shot.
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Once you have that information I don't think you'll have any trouble.
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How much elastic or compressive force must the incline exert to support the cart, and what is the direction of this force?
answer/question/discussion: ->->->->->->->->->->->-> :
Im not sure how much force the incline must exert but I would assume the direction of this force is perpendicular to the incline
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If no other force is exerted parallel to the incline, what will be the cart's acceleration?
answer/question/discussion: ->->->->->->->->->->->-> :
I know the acceleration of gravity is 9.8m/s^2 but I do not know how to calculate the acceleration using that number on a 30 degree incline
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Check my notes, work carefully through Introductory Problem Set 5, then give this another try.
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