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Latest Version Download

Digital Library

  1. 20170803gravity.epub updated with better simulations
  2. 20161216gravity.epub after Dropbox Public folder fail and added sound API
  3. 20161208gravity.epub after Professor Felix Singapore visit and end of year review.
  4. 20160707gravity.epub after IJC's bug fix for Newton's Mountain Model 8,8.1,8.2 South Pole to be correct, Binary stars with draggable velocities for more open exploration
  5. 20160701gravity.epub after YJC's review, has better design, new 2 mass simulations, and the 3D kepler's system requested by YJC.
  6. 20160526gravity.epub improved better user interface dropdown menu, bug fix for gravity11g


  1. iBook (require any of the 51 countries supported by ibook, excluding Singapore iTunes account, please use the Digital Library copy link above )
  2. Google Gbook Book

Older versions

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This interactive Gravity Advanced Level Physics chapter textbook works on both Android and iOS, offering a gorgeous, full-screen experience full of 15+ interactive simulations even 3D are available at the 3D geostationary orbits simulation, animated pictures and static photos, and links to videos on Youtube. No longer limited to static pictures to illustrate the text, now students can play and conduct mathematical modelling pedagogy developed by the Author using the Open Source Physics/Easy JavaScript Simulations. They can flip through a book by simply sliding a finger along the bottom of the screen. Highlighting text, taking notes, searching for content, and finding definitions in the glossary are just as easy. And with all their books on a single device, students will have no problem carrying them wherever they go.

The content are originally based on lectures notes from Yishun Junior College, Singapore.

photo from Leong Tze Kwang.

The content are licensed Creative Commons Attribution ShareALike CC-BY-SA, and the Open Source Physics/Easy JavaScript Simulations are licensed Creative Commons Attribution ShareALike Noncommercial CC-BY-SA-NC.

If you are having problem getting this interactive textbook, try this link


For Teachers

Best Android Experience: PlayBook download with links to simulation launch in Chrome browser full screen.

Best Apple Experience: iBook download with iPads, simulations launch out or in ibook itself.

To submit to Google, use this link

To submit to Apple, use the iTune Producer App on iMac

Software Requirements

epub3 reader such as

Google Play Store Android Gitden Reader App,

Apple iBook app

ChromeWeb Extension for computer

  1. 1st choice Readiator EPUB Reader offered by shenzhuxi
  2. 2nd choice Readium offered by 


Francisco Esquembre, author of Easy JavaScript Simulation Authoring Tool, an Open Source Physics project.

Loo Kang WEE Lawrence is currently educational technology specialist II at the Ministry of Education, Singapore. His open source physics contribution garner awards including UNESCO King Hamad Bin Isa Al-Khalifa Prize for the Use of ICTs in Education 2015Singapore Public Service PS21 Distinguished Star Service Award 2014 and Best Ideator 2012, Ministry of Education, Singapore, Best Innovator Award 2013 and Excellence Service Award 2012.

Leong Tze Kwang photographer for the cover page of chapter.

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Survey Data

Survey results on Gravitation ebook from JC1 seniors workshop on 15 Oct 2015
Sample size: 15  
S/no Questions Answers
1 How useful is this ebook, on a scale from 1 - 10? 7.27
2 Would you use this ebook, on a scale from 1 - 10? 6.4
Why? Useful for easy visualisation
Learning become more interesting [2]
Better than boring lessons as this is more interactive [2]
Very interesting and good for concept but once is enough for understanding
Easier to visualise  as compared to paper but may not be able to understand fully the use of each function
Prefer lecture notes but this may come in handy when I need clarification
Might be difficult to use but it is helpful for students to understand better
Useful but boring
Might not have additional time to use it
Not a system I am used to
A little time-consuming
I may not know how to use certain SIM and hence not using it
The SIM is repetitive and the content is heavy
3 Should we replace lecture notes with this ebook? Yes [3]; No [12]
Why? Definitely gives a clearer explanation
It is more interactive
Environmentally friendly and useful
Not everyone has a iPAD or tablet. I prefer paper. [4]
It should be supplementary/additional learning material, not to replace notes [5]
Lectures notes are more informative
4 Which is your favourite SIM? 3D Geostationary satellite model [14]
Binary stars model



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4.9583333333333 1 1 1 1 1 1 1 1 1 1 Rating 4.96 (12 Votes)