Wright State University Lake Campus/2016-9/Phy1110/log

29-Aug

Your account will span Wikiversity, Wikipedia, Commons, and Wikibooks.

1. No username can be anonymous on this campus. Your classmates will likely discover your identity. One option is to quasi-violate Wikimedia policy and have a "public" username, and different private one.
2. You are advised not to worry about previous consideration and pick a "permanent" username that you might use for the rest of your life. Pick an unembarassing username that not too long, avoid spaces and other odd symbols.
1. Use one you already know
2. Use one that you might forget, but give me the password. (Never give your "important" passwords to anybody; but keep in mind that very little harm is done if you give me your password

5-Sep

Lecture: Vectors

Vector, vector addition, components, unit vectors

Transformations between (magnitude,direction) and (x,y components)

12-Sep 2d smith train and Malus law lab

• Two-d Smith train
• Review studyguide
• Lab choices:

Malus law and vector components.

Next time
Run the lab 15 times and use the average.
Run in a channel to control the balls movement.
Have a slower acceleration.

Present: '''Rimstock''', EmilyR, KTangeman26, NG18, Brackattack25, Crind



19-Sep velocity and acceleration

• Monday Lecture: Worked on Velocity and acceleration, focusing on questions pertaining to finding the acceleration. We did all but the first question ("When a table cloth is quickly pulled out from under dishes, they hardly move. This is because ..."),

26-Sep force table lab

Lab on force table: Reports on S-subpage to log. Rimstock

${\displaystyle x+\theta =180\deg }$
${\displaystyle \tan \theta ={\frac {3}{4}}}$
${\displaystyle \theta =\left(\operatorname {arctan} {\frac {3}{4}}\right)\cdot {\frac {180\deg }{\pi }}=X}$
${\displaystyle 180-X=\theta _{\text{actual}}}$

${\displaystyle \theta _{\text{actual}}=180-\left(\operatorname {arctan} {\frac {3}{4}}\right)\cdot {\frac {180\deg }{\pi }}}$

10-Oct Newton's III law

Can we "derive" Newton's 3rd law?
1. Take attendance on Guy vandegrift for lab 12 October 2016 (UTC)
2. Guided derivation of Newton's third law. In the figure to the right, let is pretend we don't know how the string interacts with the two masses, but assume that a force

T1 [1] acts on m1 and the force T2 acts on m2. Take both T1 and T2 to be positive quantities, but use your intuition to guide you as to whether the force is to the right (positive) or to the left (negative). Assume both masses are initially at rest and that the net force is to the left. Write down Newton's third law (Fe=ma) for 3 (three!) masses: m1, m2, and Σm =m1 + m2

1. The figure calls these forces F12 or F21, but I find this notation somewhat confusing. You need such notation if more than two objects are interacting.

24-Oct Centripetal force lab

Your report shall be handwritten on paper. We will cut and paste your efforts and try to produce a pdf file or a svg file to post on Wikiversity.

1. Sketch device in stationary mode, labeling rotating mass, m, hanging mass, M, radius of orbit, r. Write an equation involving the spring's force, FS, the gravitational acceleration, g, any other variable that has been defined.
2. Set up the device and quickly[1] measure m, M, r.
3. Derive a formula for FS involving your measured values. This formula is essential and needs to be prominently displayed in the report. Also calculate this force in Newtons. Perhaps include an uncertainty in this value.
4. This is a "verification experiment", otherwise known simply as an experiment. We need two measurements of FS that might or might not be equal to each other. Is there any other way to measure FS ? Define v as the speed, and T as the orbit's period and write down two equations: One involves FS and a=v2/r and the other involves v, r, and T. Your prof will write them on the board and discuss.

Footnotes

1. It's always a good idea to quickly measure and calculate first before doing it carefully

14-Nov Kepler's III, error averaging of times, 3 mass pendulum

1. Proved kepler's III law and applied concept to g as function of r, T, m, M in whirly jig lab.
2. Verified that it seems to be better (?) to measure 10 cycles and divide by 10 to get period. Promise to continue w error propagation.
3. Watched part of the mit video and made our own 3 mass system and created video with Rimstock, KTangeman26, ng18, CRind, Emily_R, Brack_Attack25, and Guy vandegrift