## Wednesday, July 29, 2015

### EJSS vector sum model

Update 31 July 2015 now with examples by Ezzy Chan

## Example 1 |V₁|=120,ϑ₁=60°,|V₂|=80,ϑ₂=105°

 |V₁|=120,ϑ₁=60°,|V₂|=80,ϑ₂=115° example 1 by ezzy chan
 |V₁|=120,ϑ₁=60°,|V₂|=80,ϑ₂=115° example 1 solution by ezzy chan

## Example 2 |V₁|=12,ϑ₁=0°,|V₂|=9,ϑ₂=90°

 |V₁|=12,ϑ₁=0°,|V₂|=9,ϑ₂=90° solution by ezzy
 |V₁|=12,ϑ₁=0°,|V₂|=9,ϑ₂=90° example by ezzy

## Example 3 |V₁|=400,ϑ₁=-90°,|V₂|=500,ϑ₂=60°,|V₃|=500,ϑ₃=120°

 |V₁|=400,ϑ₁=-90°,|V₂|=500,ϑ₂=60°,|V₃|=500,ϑ₃=120° example by ezzy

 |V₁|=400,ϑ₁=-90°,|V₂|=500,ϑ₂=60°,|V₃|=500,ϑ₃=120° example 3 solution by ezzy

EJSS vector sum model

## Originally by

Derived work by Wee Loo Kang under creative commons http://creativecommons.org/licenses/by/2.5/tw/deed.en

You are free:
to Share — to copy, distribute and transmit the work
to Remix — to adapt the work

## Under the following conditions:

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## reference:

### EJSS Standing Wave in Pipe Model

EJSS Standing Wave in Pipe Model

## Standing waves in a pipe

Let us consider a narrow pipe along the OX axis. Each end may be open or closed. The simulation will display the first 5 normal modes, which are
u(t,x) = A sin(n π x) cos(ω t + δ) when both ends are closed.
u(t,x) = A sin((n-1/2) π x) cos(ω t + δ) when the left end is closed and the right end open.
u(t,x) = A cos((n-1/2) π x) cos(ω t + δ) when the left end is open and the right end closed.
u(t,x) = A cos(n π x) cos(ω t + δ) when both ends are open.

Units are arbitrary
Below you may choose the mode n = 1, ...,5, for the various modes of standing wave formation closed endsas well as the animation step Δt.
The simulation shows the displacement field u(t,x) and the pressure p(t,x) as functions of x at each time t.
In the lower animation you may see the evolution of the position x + u(t,x) of several points and a contour plot of p(t,x) (lighter/darker blue means higher/lower pressure).
Optionally one can see the nodes where the displacement wave vanishes at all times.
Scale has been arbitrarily enhanced to make things visible; but keep in mind that we are considering very small displacements and pressure changes in a narrow pipe.
Put the mouse point over an element to get the corresponding tooltip.

## Activities

1. Compute the position of the nodes for mode number n in the four considered cases.
2. Use the simulation to check your calculation.
3. Where are the pressure nodes in the different cases?
4. Which is the relationship between the displacement and pressure waves? How does it appears in the animation?

## Authors:

This is an remixed by lookang and tina, of the English translation of the Basque original for a course on mechanics, oscillations and waves.
It requires Java 1.5 or newer  is written now in Javascript and was created by Juan M. Aguirregabiria with Easy JavaScript Simulations (Ejss) by Francisco Esquembre. We all thank Wolfgang Christian and Francisco Esquembre for their help.

## Tuesday, July 28, 2015

### Research gate part3

18 august part5

04 august 2015 part4

### Vernier caliper and micrometer computer models using Easy Java Simulation

Thank you Physics Education
i also submitted to https://www.ictlt.com/
http://ictlt2016.exordo.com/#submissions/all/23/view

Title
Vernier caliper and micrometer computer models using Easy Java Simulation and its pedagogical design feature-ideas to augment learning with real instruments
Authors
1. Mr. Lawrence WEE (Ministry of Education, Singapore)
Abstract
This article presents the customization of EJS models, used together with actual laboratory instruments, to create an active experiential learning of measurements. The laboratory instruments are the vernier caliper and the micrometer. Three computer model design ideas that complement real equipment are discussed in this article. They are 1) the simple view and associated learning to pen and paper question and the real world, 2) hints, answers, different options of scales and inclusion of zero error and 3) assessment for learning feedback. The initial positive feedback from Singaporean students and educators points to the possibility of these tools being successfully shared and implemented in learning communities, and validated.
Educators are encouraged to change the source codes of these computer models to suit their own purposes, licensed creative commons attribution for the benefit of all humankind.
Video abstract: http://youtu.be/jHoA5M-_1R4
Topic Areas
• Sciences
Main Presenter Author Contact Number
92475573
Designation
Specialist
weelookang@gmail.com
Conference Strand
Connecting Educators as Learning Designers
Target Audience
Teacher-Leaders (e.g. Senior / Lead / Master Teachers, Heads of Departments, School Staff Developers, and ICT Mentors)
Target Audience (Secondary)
Teacher-Leaders (e.g. Senior / Lead / Master Teachers, Heads of Departments, School Staff Developers, and ICT Mentors)

History of Presentation
No
Presentation Format
E-Poster Exhibition
Submission Date
July 25, 2015 18:33
Is It a Student Paper?
No
Latest Update
July 25, 2015 19:50
Submission ID
23

### Understanding resonance graphs using Easy Java Simulations (EJS) and why...

Thank you Physics Education
i also submitted to https://www.ictlt.com/
http://ictlt2016.exordo.com/#submissions/22/
Title
Vernier caliper and micrometer computer models using Easy Java Simulation and its pedagogical design feature-ideas to augment learning with real instruments
Authors
1. Mr. Lawrence WEE (Ministry of Education, Singapore)
Abstract
This article presents the customization of EJS models, used together with actual laboratory instruments, to create an active experiential learning of measurements. The laboratory instruments are the vernier caliper and the micrometer. Three computer model design ideas that complement real equipment are discussed in this article. They are 1) the simple view and associated learning to pen and paper question and the real world, 2) hints, answers, different options of scales and inclusion of zero error and 3) assessment for learning feedback. The initial positive feedback from Singaporean students and educators points to the possibility of these tools being successfully shared and implemented in learning communities, and validated.
Educators are encouraged to change the source codes of these computer models to suit their own purposes, licensed creative commons attribution for the benefit of all humankind.
Video abstract: http://youtu.be/jHoA5M-_1R4
Topic Areas
• Sciences
Main Presenter Author Contact Number
92475573
Designation
Specialist
weelookang@gmail.com
Conference Strand
Connecting Educators as Learning Designers
Target Audience
Teacher-Leaders (e.g. Senior / Lead / Master Teachers, Heads of Departments, School Staff Developers, and ICT Mentors)
Target Audience (Secondary)
Teacher-Leaders (e.g. Senior / Lead / Master Teachers, Heads of Departments, School Staff Developers, and ICT Mentors)
History of Presentation
No
Presentation Format
E-Poster Exhibition
Submission Date
July 25, 2015 18:33
Is It a Student Paper?
No
Latest Update
July 25, 2015 19:50
Submission ID
23

## Monday, July 27, 2015

### EJSS Fermat's principle refraction model

In optics, Fermat's principle or the principle of least time is the principle that the path taken between two points by a ray of light is the path that can be traversed in the least time.

EJSS Fermat's principle refraction model

If possible, let as many know that we can harness the power of OSP for the benefit of all, licensed creative commons attribution, not all rights reserved, just the rights to be named in the our remixed derivatives will suffice.
Our purpose to help the world at our otherwise untapped intellectual cost, a small price we can pay for the greater good of all educational system in the world.

## Saturday, July 25, 2015

### E posters for http://ictlt.com

The system ex ordo is quite good.

Some areas of improvement are.
Remember submissions emails, designations, head of school name and emails alternate emails.
Shows eposter file name after submission.

## Friday, July 24, 2015

### 2010 Eurovision winner: “Satellite”

2010 Eurovision winner: “Satellite”

Read the paper: A geostationary Earth orbit satellite model using Easy Java Simulation

Loo Kang Wee and Giam Hwee Goh 2013 Phys. Educ. 48 72

http://iopscience.iop.org/0031-9120/48/1/72/article

### Researchgate part2

Most views of the week. Who would have guess it only takes 27 views?

## Thursday, July 23, 2015

### EJSS Transverse Wave Model

EJSS Transverse Wave Model

## Monday, July 20, 2015

### Greetings from Philippines!

Greetings from Philippines!

### Greetings from India!

i wonder if the paper is finally published? this time is professor Radhakrishnamurty Padyala's request.

## Friday, July 17, 2015

### Rich resources by Seng Kwang

Must find time to speed read all his posts.
Interesting find on the geogebra PV diagram.

http://physicslens.com/tracker-for-understanding-bouncing-ball-problem/

## Thursday, July 16, 2015

### now that something you dont see everyday

now that something you don't see everyday.
thank you https://www.researchgate.net/profile/Loo_Kang_Wee/stats

## Monday, July 13, 2015

### ground breaking news! I have developed fullscreen capability for EJSS

ground breaking news! I have developed a way to launch full-screen capability for EJSS. It now looks like a web-app.

in my testing, it works beautifully on SumSung Note 3 5.5 inch screen in portrait orientation.

## Friday, July 10, 2015

### iCTLT 2016 – Online Submission Chair and User Guide

i am conference chair, need to watch these video. Pretty immpressive system http://www.exordo.com/
iCTLT 2016 – Online Submission Guide
2016, 28-31 March
5th International Conference on Teaching and Learning with Technology
http://ictlt2016.exordo.com
2. Setting up initial conference: https://www.youtube.com/watch?v=xmw7ABhzLIs
3. Setting up Abstract & paper submission: https://www.youtube.com/watch?v=pj8EXiK1J5s
4. Setting up the Peer Review Marking Scheme: https://www.youtube.com/watch?v=HxmVKXiRJNw
(Note: These are basic marketing videos which might not “cover” some new features or
customization)

## Tuesday, July 7, 2015

### Greetings from Brazil! Thank you

Thanks to professor in Brazil for the email for affirming my contribution to use of technology for physics education.

## Friday, July 3, 2015

### EJSS Vernier caliper model

Finally re creating can be done quickly about 2 days.
Need more time to better the codes for hints and special cases.

## Thursday, July 2, 2015

### EJSS Micrometer Model

successfully re -created on Easy JavaScript Simulation EJSS!

## Micrometer Model

Micrometers use the principle of a screw to amplify small distances that are too small to measure directly into large rotations of the screw that are big enough to read from a scale. The accuracy of a micrometer derives from the accuracy of the thread form that is at its heart. The basic operating principles of a micrometer are as follows:
The amount of rotation of an accurately made screw can be directly and precisely correlated to a certain amount of axial movement (and vice-versa), through the constant known as the screw's lead. A screw's lead is the distance it moves forward axially with one complete turn (360°). (In most threads [that is, in all single-start threads], lead and pitch refer to essentially the same concept.)
With an appropriate lead and major diameter of the screw, a given amount of axial movement will be amplified in the resulting circumferential movement.

## The micrometer has most functional physical parts of a real micrometer.

Frame (Orange) The C-shaped body that holds the anvil and barrel in constant relation to each other. It is thick because it needs to minimize expansion, and contraction, which would distort the measurement. The frame is heavy and consequently has a high thermal mass, to prevent substantial heating up by the holding hand/fingers. has a text 0.01 mm for smallest division of instrument has a text 2 rounds = 100 = 1.00 mm to allow association to actual micrometer
Anvil (Gray) The shiny part that the spindle moves toward, and that the sample rests against.
Sleeve / barrel / stock (Yellow) The stationary round part with the linear scale on it. Sometimes vernier markings.
Lock nut / lock-ring / thimble lock (Blue) The knurled part (or lever) that one can tighten to hold the spindle stationary, such as when momentarily holding a measurement.
Screw (not seen) The heart of the micrometer It is inside the barrel.
Spindle (Dark Green) The shiny cylindrical part that the thimble causes to move toward the anvil.
Thimble (Green) The part that one's thumb turns. Graduated markings.
Ratchet (Teal) (not shown ) Device on end of handle that limits applied pressure by slipping at a calibrated torque.