Thank you for the movie. I know much more what you might want. But I still have some more questions.
Do you want to simulate a ball attracted by a magnet or you want to simulate a charged particle moving straight, and then attracted by another changed particle.
Please write down the purpose for the simulation you want.
Is it for teaching some physics concept? What is the physics you want to be simulated.
Let me know more about what you really want. Please write more sentences!