In an experiment, three microscopic latex spheres are sprayed into a chamber and become charged with +3e, +5e, and −3e, respectively. Later, all three spheres collide simultaneously and then separate. Which of the following are possible values for the final charges on the spheres? Select two answers. (a) $+4e,-4e,+5e$
(b) $-4e,+4.5e,+4.5e$
(c) $+5e,-8e,+7e$
(d) $+6e,+6e,-7e$

Video Transcript

This is College Physics Answers with Shaun Dychko. When these three latex spheres collide with each other, they are going to exchange charges and the law of conservation of charge means that the sum of the charges has to remain the same. So we have positive 3, positive 5 and negative 3 and that sum is 3 plus 5 minus 3 which is 5. So any answer here that has a total of 5 will work. So 4 minus 4 is 0 plus 5 makes 5; this has charges that are not integers so that's definitely not going to work, we don't even have to add them. This one is not a total of 5, it's a total of 4 and so that doesn't work. And this one is positive 12 minus 7 which is 5. Yeah. Good. OK. Good. There, (a) and (d) work.