wolfram alpha - kronig-penney model

The Kronig-Penney Model from the Wolfram Demonstrations Project by Michael Croucher

energy minor

so many things on the plate.  just want to record this:

2005	The Science of Energy (4) A descriptive course covering energy resources, production, and consumption in the 21st century. Energy input and output of physical systems such as household appliances and modes of transportation. Not for credit in Physics major.

From CSU-East Bay http://www20.csueastbay.edu/ecat/undergrad-chapters/u-phys.html#major-req-bs

I'd like to teach a similar course.  So many neat ideas to explore here, and over time develop high-quality curricula with materials...

First successful prototype for undergrad physics labs

First prototype of Arduino for linear motion labs....

Arduino with sonic ranging module HC - SR04 (from the specs sheet):

Ultrasonic ranging module HC - SR04 provides 2cm - 400cm non-contact

measurement function, the ranging accuracy can reach to 3mm. The modules

includes ultrasonic transmitters, receiver and control circuit. The basic principle

of work:

(1) Using IO trigger for at least 10us high level signal,

(2) The Module automatically sends eight 40 kHz and detect whether there is a

pulse signal back.

(3) IF the signal back, through high level , time of high output IO duration is

the time from sending ultrasonic to returning.

Test distance = (high level time×velocity of sound (340M/S) / 2,

So what is the device doing?

The device measures the time that it takes for a sound pulse to return after bouncing off some surface and converts that value to a position.  Placing a card or hand in front of the transducer/microphone gives excellent readings as well.

Here's what a position vs. time [ x(t) ] graph looks like as I move the Arduino back and forth, bouncing the sound wave against the wall:

And the program can also output the position as a data file.  I loaded a data file into Excel:

It would be great to continue this project with the following steps:

1. log tabular data (see this and this)
2. plot v(t) and a(t) in addition to x(t) data in real time.
3. handle situation in case there is an erroneous spike
4. test the limitations of software/hardware.  Will the 40 Hz (25 ms) response of the HC - SR04 be appropriate?  How accurate/precise are our measurements?  Would using slightly better parts make a big difference?
5. test in actual lab scenario with a linear air track
1. how to arrange computers to be near lab setups?
6. develop some intriguing, real-world lab worksheet that guides students through the process as well as connects their experience to real-world applications.  Make an "instructor sheet" with concepts and ideas to plant as instructor goes around room visiting each lab group.

Resources:
Interfacing Code with the Physical World: A Crash Course in Processing and Arduino

How to visualize and save Arduino-sensed data

Longer-term questions:

1. How to make a direct real-world tie-in with as many labs as possible?
2. What activities will students respond most to?  What will be most intriguing?
3. Data analysis: should templates be provided?
4. Should these devices be ready to go or should students assemble?  (It can be as simple as plugging in 4 wires, and hitting upload to upload the arduino program.)
5. Value of written lab report: Students need to gain experience explaining and expressing scientific ideas concisely.  How can we emphasize this without placing an unreasonable time burden on the students (this is only a 1-hr credit)?  

Here's another cool idea that can be adopted (from Stanford undergrad labs):
Bernoulli's principle -- the sound can bounce off the top surface of a bucket of water, and thus flow rate can be calculated.  This can be related to the pressure at the level of a hole in the bucket, or the flow velocity -- and if a horizontal hole, the range that the water travels before hitting the floor!

data logger and analysis software, MIT

https://code.google.com/p/extrae/

Hi! I was checking about physics and science projects for arduino and came up with your page. I’m very happy to tell you that I’ve just made available an open source software for data extraction and basic analysis using Arduino, java and JavaFX. This ṕroject dates a long time ago (maybe a year or two) and we were hoping to get the time to make it available soon but we haven’t had the time to make the code “nice and tidy” (we had the project practically stopped for a year). It has MIT license (you can do anything you want with it). If you use it some feedback is very appreciated as we plan on restarting it soon.
The project’s page is :
http://code.google.com/p/extrae/
Hope you have fun with it,
Bests!

(from http://quarkstream.wordpress.com/lessons-in-arduino/)

thoughts on arduinos in PHY100L/200L labs

• Students should be left to focus on the physics, with only some awareness about the arduino and its function as a tool -- not too much (or any?) programming, and minimize technical bugs if at all possible.
• Technical issue minimization:


• possible to load routines onto multiple arduinos at once?
•  possible to load several routines onto a single arduino?  Maybe we can work-around by measuring from several channels simultaneously, and if there is a LO/HI signal then that channel is ignored in outputting to the computer...  Need to check memory requirements to estimate the size of program that is realistic on an Arduino (gut: it should work fine for having 3-5 functions, such as: send/receive audio clicks at regular intervals (~20 ms), receive IR sensor info at regular intervals (for pulley black/white or for sensor of pendulum slipping by).

Term project ideas -- into labs and demos

Force sensor
https://www.manylabs.org/docs/project/forceSensor/

Construct a force sensor using the above link as inspiration.  A simple spring will be used to move a variable resistor -- this then changes the voltage measured, which one can use to correlate with how much force one pushed on the spring.
Calibrate it.  Test it out.  What are the limits?  How sensitive is your force sensor (what is the smallest increment in force that it can detect)?



Pulley rotation sensor
https://www.manylabs.org/docs/project/pulley/

Ever wonder how an old-school mouse uses the motion of the ball to track where you are moving a cursor on a screen?  This is the same idea.  Two photo sensors are needed to determine which way the pulley is rotating.  This can be used to make precise measurements of the motion of things that are connected through the pulley, such as an Atwood's machine setup.
Once this has been constructed and the hardware works, make the device output (either to computer or LCD display) the rotational speed -- e.g., in RPMs, or rad/sec.


Egg drop
https://www.manylabs.org/docs/project/eggDrop/
(Not required to make this wireless -- can be designed so that the data is read out later)
Here you'll put an accelerometer inside with an egg in a box and measure the acceleration as the egg is dropped from a tall height (such as a second story building).  What is the max acceleration?  What acceleration breaks the egg?  How does this compare with the force needed to break a similar egg (tested, e.g., by putting weights on top of the egg)?


Sound for measuring position / speed of sound
Speaker and microphone combo allow you to measure the time that it takes for a sound wave to bounce off a surface.  Using this device along with a cart can help you measure the position of the cart at several times, ultimately letting you plot its trajectory.


light source / photosensor for detecting when something goes by

Here you will set up an LED (or laser) and send it onto a photosensor.  If something blocks the path between the laser and the photosensor, then the time should be recorded. We can use this for example to measure the oscillation period of a pendulum.

more brainstorming

notes from a recent meeting with Evan, Tom, and Nelson:

idea: concepts building on each other

encoder --> potentiometer
motor
pendulum mounted from a linear stage (too complicated?)


it's important to isolate physics concepts without too much technical stuff.  more technical stuff --> more chance of technical issues --> less chance of a physics concept being driven home to student.

where in the U.S. (or world) are the most interesting and creative freshman physics labs being done?


quantity comparisons -- e.g. power from a solar cell

tripping a circuit (evan)

integrate with ME, MET, FET tracks.  hardware/software..

2 pt vs 4 pt measurement

kappa/sigma -- measure each/

tom: will forward labs used in instrumentation

goerge weissensides -- how to write a journal publication  (??? could not find... evan?)

tom thinks it might be a good idea to have students write a lab report, or at least an abstract.

idea: potentiometer


we plan to meet with mike holden and ask about his experiences with microcontrollers (arduinos specifically?) and education.

PHY is the foundation of many students' experiences.

some senior design projects seemed ambitious.

lab idea -- characterize several unknown materials.

ohm's law, fourier's law, voltage, temperature

student competitions: rally challenge, john rogers -- cal sailing team robot


john fisher