I dont know if I should post this in this forum..(Please tell if this out of its domain) We are carrying out different experiments in a cubical room. 1.On adjacent (perpendicular) walls we have, for the first expt., two identical balls touching the floor which are shot towards each other (normal to the walls) such that in 1 subcase they undergo a perfectly elastic; in the other a perfectly inelastic collision. By simple calculation we can determine the subseqent trajectories of the masses.. 2.Arrangements are same except that we replace the balls with two highly powerful electron guns (which again shoot "masses") such the beams again "collide" at the centre. Now what will be the subsequent trajectories of these electrons? (General observations suggest that that they will just maintain their initial paths as evident if we light 2 torches in this way, yes??. But does the ans lie only in the principle of superposition of waves wont the charges of the electrons play their part in deciding their tragectories. If yes, then what would be the paths?) 3.Further, if in the 1st expt. we eliminate the frame's gravity (conduct the expt. on a satellite,etc.) what would be the initial & final trajectories just after release of the balls in the 2 subcases? 4.Moreover, if the electron guns are replaced by photon guns & we are lucky enough to have a collision, can we expect a result similar to any one of the above? Lastly, I hit upon this stuff in the bathroom today. I am on pre-college vacation & would not like to be warned about posting things in the homework forum (in a nutshell: this is not homework)..