# Wright State University Lake Campus/2017-9/Phy1050/log

Wright State University Lake Campus/2017-9/Phy1050/Studyguide .. Wright State University Lake Campus/2017-9/Phy1050/Syllabus .. wright.miraheze.org

### M 28 August 2017 (UTC)

Showed card game. Introduced Studyguide. Did first quiz on motion. Don't sweat these calculations if you can't do them. You have other ways to succeed in this class.

### T 29 August 2017 (UTC)

Attendance policy: Allowed to miss 15 days without penalty. Nominally, you must attend 60 days to get 100%.

${\displaystyle G={\frac {D}{55}}\times 100\%}$

and D is the days that you attend, OR 55 if you attend more than 55 days.

Polarizing filters. Maybe do another wikiquiz.

### T 5 September 2017 Syllabus

Test prep: Questions 1-14 of second quiz Special:Permalink/1415990 has been discussed. (quiz called "velocity and acceleration"

### transclusion deactivated by a nowiki tag

{{cot|[[Physics and Astronomy Labs/Uniform acceleration tapping basketball with spitwads#How_Things_Work_Lake_Campus_Fall_17|Hidden transclusion <sup>--click to visit</sup> ]] .. click bar to see or hide}}

{{cob}}


### M 9 Sep

Did you get email on test postponement? What did we do Thursday and Friday?

Want more?

### T 12 Sep

• Go to Studyguide: 7/16 from 1409885 to b_waves_PC. Also: NOT ON THIS TEST: What happens to the wavelength on a wave on a stretched string if the wave passes from lightweight (low density) region of the rope to a heavy (high density) rope? Question 14 on studyguide.

### Wed 13 Sep

natural 5/3 = 1.6667... http://www.wright.edu/~guy.vandegrift/Talks/cello.mp3
scientific 29/12 = 1.681793...http://www.wright.edu/~guy.vandegrift/Talks/piano.mp3

as Bach wrote it http://www.wimmercello.com/images/bachs1a.gif

### Monday 18 September Optics (for Test on Wednesday)

also before the next test

I like this one

### Monday 2 October Newton's Dark Secrets

#### Summary of transcript

1 Newtwon wrote in code. Much of of his personal writings were never really understood as late as 1937.

2 3 4

5 An apple speeds up as it falls. At every instant in time it seems to have a certain speed. How do you mathematically describe this "instantaneous" velocity? ${\displaystyle v_{instant}={\frac {x_{2}-x_{1}}{t_{2}-t_{1}}}}$ when the two times are nearly the same. See also File:Tangent as Secant Limit.svg

6 7 8 9 10 11 12 13 14 15 16

### Wed oct 4 newton's cannon

File:Bisection_method.svg and wikipedia:Bisection method and Newton's cannon "${\displaystyle 6250m/s 4 October 2017 At 6250 we missed the center of the cannon by approximately on ball diameter. At 6200 it seemed to go higher. The for this second one was 3min32sec=212sec

4411 <Min <4411.5

### Thur oct 5 curve fit newton's cannon

Procedure:

1. Measure distance "as crow flies" for v = 1000 and 4000 m/s.
2. Predict distance for v=2000. Make a sketch showing how a graph and similar triangles would permit you to find a formula. You can also get the formula by something called Regression_analysis
3. Measure and calculate Big/Small and also percent error. The latter is (Measured−True)/True. You can report Big/Small as off by a factor of .... For small errors (less than about 10% or so, they essentially give the same information).
4. Fit your three points to a parabola. It's best not to use Excel curve fit. There is an Excel extension, but it is more convenient to search the internet for "regression" fitting.
5. Now use your parabola to predict the distance for v=3000. Measure and compare as before.

We collected this data (USING A REDUCED IMAGE ON THE SCREEN):

initial
speed  DISTANCE
m/s     CM
1000    7.2
4000    36.9
2000    12.4
3000    19.9


## Upcoming lectures

### Advanced curve fitting with Newton's cannon

• Goal: Find the so-called "parabolic" curve File:Kepler_orbits.svg. Or more precisely, be able to predict periods for near-parabolic ellipses by extraplating. Let y=1/t, where t is the time to crash, and do a fit for y=y(v), where v is the initial speed. Data
v      t
6100   3m00s
6200   3m32s
6300   6m25s


### Newton's_cannon_alarm_clock

Data taken in classroom: timercannon

v          t
6300
6320


### Test 3 global warming links

• Estimates of rise
1. nationalgeographi.com (google) Average temperatures have climbed 1.4 degrees Fahrenheit (0.8 degree Celsius) around the world since 1880.
2. Summary of findings - Muller (berkeleyearth.org)
• Muller lectures: