Are you sure students can learn physics when they play with the scene at http://www.barechoons.com/content/view/27/#josc358 ?
For Interactive Physics, I believe instructor need to design scene ,and ask the right questions to make the activity effective.
'Interactive Physics' provide possibility for students to design scene to find out the result, but it did not provide the reason why it is working that way? And EJS can do much better if we want to help student with the physics model. And that is the reason why I devoted my time to EJS.
Yes. It is possible to create something similar to interactive physics with EJS or even to create another similar software.
However, I think it is designed for different teaching purpose. You are welcomed to build modules with EJS to have similar environment like "interactive physics". But I will keep working with EJS to create small modules for students. (Similar effect but different approach)
You might want to try out modellus (http://modellus.fct.unl.pt/). May be that is what you are looking for. I did not select modellus because it was not written in JAVA. I have asked them to develop java version, and they just have beta version available recently.