Hi,
I will try to write more sentences to be the clearest it's possible to be. But it's such a long time I've not written in Shakespeare's language that it's sometimes difficult to find the correct word.
I'm teaching in "college" (in France it means for children between 11 and  15 years old) and this year, we have been told by our hierarchy that we have to speak about gravitation without using vectors and using the word "force".

So we have to make analogy with slingshot and magnet to make students imagine what gravitational interaction is.

I allways use computer tools to teach and since all my students in third class have laptop in school, for this course I would like to make them work on it.

My favorite tools to let students work in autonomy are Didapages and Exelearning. They let you insert what kind of media you want and to create test for being sure everything has been understood.

With the first one, I made books like
http://gwenaelm.free.fr/Physique/Physchim/capes/Doc/Didapages/Forces/index.html
or
http://gwenaelm.free.fr/Physique/Physchim/capes/Doc/Didapages/Vitesse/index.html

and with the  other one, my only work from now on is this course on oscilloscope
http://gwenaelm.free.fr/Physique/Physchim/c03/Electricite/Html/Oscillo-ol/index.html

So, to reply to your questions I just need to show children that a magnet can modify trajectory of the ball without touching it, that a remote interaction can exist so they will think about the same kind of intercation for Earth and Moon interactions.

Regards,