#$&*
course Phy 201
Instructions:1.Copy this document into a text editor, such as notepad.
2. Insert your answers between lines marked **** and #$&*. Do not insert anything into the lines so marked.
Do not eliminate anything that appears in this document. Insert as indicated, Adapted from spiral outline: units, percent difference, etc.
3. but otherwise do not make any changes to what you see here.
4. Submit a copy of your completed document using the Submit Work Form at http://vhcc2.vhcc.edu/dsmith/submit_work.htm .
Do the following calculations with fractions. This should take you 5 minutes or less: Do not use a calculator. You can do all the numerical calculations if you know the multiplication facts for single-digit numbers.
Each answer should be typed as a sequence of numbers, letters, slashes , asterisks and parentheses. If you have questions then please show some of the steps of your work, and you will ordinarily be asked to do so. For this document, however, just the answers will be sufficient. On these questions, I'll usually be able to figure out what you've done from your answers.
(1/2) * (3/4)
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3/8
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(12/5) * (25 / 21)
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20/7
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(4/3) * 3
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4
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(5/8) * 16
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10
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(5/9) / (3/4)
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5/12
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(13/25) / 2
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13/50
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12 / (2/3)
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18
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(4 / 3^2) * 3
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4/3
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(a/b) * (c/d)
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ac/bd
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(a/b) / (c/d)
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ac/bd
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@& ac/(bd) would be the result for (a/b) * (c/d). This question is (a/b) / (c/d).*@
(a/b) * c
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ac/b
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a / (b / c)
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ac/b
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(a/b) / c
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a/bc
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(a / b) / b
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a/b^2
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(a / b^2) * b
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ab/b^2
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@& b / b^2 = 1 / b, so this simplifies to a / b.*@
(a / b^2) / b
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a/b^3
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Now do the following calculations:
(m / s) * s
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m
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kg * (m / s^2)
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mkg/s^2
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(m/s^2) * s
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ms/s^2
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@& This simplifies further, to m / s.*@
(m/s^2) * m
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m^2/s^2
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(kg * m / s^2) / (m / s)
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Kg/s
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5 m * (1 km / (1000 m) )
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1/200km
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80 ft * (31 cm / ft)
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2480cm
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20 dollars * (100 cents / dollar)
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2000cents
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12 pounds * (9.8 Newtons / (2.2 pounds) )
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53.45Newtons
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Now answer the following:
Work out and show units in every step:
If F = m a, then if m = 5 kg and a = 3 m/s^2, what is the value of F?
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5kg*3m/s^2= 15kgm/s^2
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If F = m a and F = 15 pounds when a = 5 feet / second^2, then what is m?
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15pounds=m*5ft/second^2, then 15pounds second^2/5 feet= 3pounds second^2/feet
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If KE = 1/2 m v^2 with m = 2 kg and v = 4 m/s, then what is KE?
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½*2kg*4m/s= 8kgm/2s= 4kgm/s
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@& v^2 would be (4 m/s)^2, which is equal to 4^2 m^2 / s^2 = 16 m^2 / s^2.*@
If F = k Q q / r^2 with k = 9 GigaNewton m^2 / C^2, Q = 2 C and q = 3 C with r = 10 m, then what is F?
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9GNm^2/C^2*2C*3C=54GNm^2/100m^2= 27/100GN= 0.27GigaNewton
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@& Small arithmetic error: 54/100 reduces to 27/50, not 27/100, and gives you .54.
Well-done nevertheless.*@
@& You did really well with this. You had a few errors, so check my notes, but you very clearly know what you're doing here and shouldn't have any trouble with units in this course.*@