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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.
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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 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: ->->->->->->->->->->->-> :
5 cm; 8 cm.
C = [sqrt] 5^2 + 8^2
C = 9.4 cm
9.4 cm – 7.5 cm = 1.5 cm
0.7 N * 1.9 cm = 1.33 N
Good. Consider the following:
0.7 N / cm * 1.9 cm = 1.33 N.
Let me know if you have a question about the meaning and usefulness of that N / cm unit. Your original calculation was N * cm, which would give you N * cm.
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• What is the vector from the first point to the second?
answer/question/discussion: ->->->->->->->->->->->-> :
x = 5 cm
y = 8 cm
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• What is the magnitude of this vector?
answer/question/discussion: ->->->->->->->->->->->-> :
C = 9.4 cm
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• 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: ->->->->->->->->->->->-> :
5 cm / 9.4 cm = 0.53
8 cm / 9.4 cm = 0.85
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• 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: ->->->->->->->->->->->-> :
1.3 N * 0.53 = 0.69 N
1.3 N * 0.85 = 1.1 N
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• What are the x and y components of the new vector?
answer/question/discussion: ->->->->->->->->->->->-> :
x = 0.69, y = 1.1
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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.
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1 hour
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12/2/2010 9 am EST
#### Resubmission of this assignment.
&#Good responses. See my notes and let me know if you have questions. &#