Perhaps the discussion is dead and gone, but there are still reopen votes on the question being discussed, and1 I'd like to bring in a few additional points.
First, I suggest looking at the question (v4), the last version prior to the question's closure. A decent explanation is provided for the motivation for the question, as well as the process leading up to the question. However, look at the third-to-last sentence of this revision, the heart of the question itself:
But I don't know velocity of this molecule that I need for calculating rate of evaporation.
This sounds an awful lot like another way of asking the question:
How can I find the velocity of this molecule in order to calculate the rate of evaporation?
I would certainly vote to close that if I saw it (I was not one of the original reviewers, by the way) as violating How do I ask homework questions on Physics Stack Exchange?. I've read through your comments, Michael, including this one, in which you state quite clearly that parts (a) and (b) were not intended to be solved analytically. Yet it seems to me that this is indeed an analytic task.
However, more important, at the moment, is the current state of the question (v11). The asker seems to have switched the focus to something that is decidedly not quantitative or analytic, and more like what you were describing as the intended way for the student to solve the problem. For this reason, I have voted to reopen the question.
You can stop reading there if you want; the rest of this answer is largely unimportant in comparison. But I'd like to say a few things.
First, take a look (if you haven't already) at this chat message, which quotes this (deleted) comment:
@MichaelA.Gottlieb from your comments I wonder if you may be confused about the purpose of putting questions on hold? It doesn't (usually) mean "we don't want this", it means "this needs improvement", and should be accompanied by some information about what needs to be improved. We often hold comment discussions with the poster to work out how to improve the question while it's on hold, and then the hold gets removed afterwards. Also: your old reputation ("points") isn't lost, it's out there in your old account and we can merge it into your current one. — David Z ♦ 5 hours ago
I've reviewed many more close vote suggestions than reopen vote suggestions, most likely by an order of magnitude. The reason isn't because I take sadistic pleasure from closing lots of questions, but because I would be that most closed questions aren't improved.
What's the reason? I don't know. It's clear how you can get your question reopened (see How do you reopen a closed question?, Nudge users to fix their closed questions themselves before calling others to reopen it, and Make the FAQ clear on how a question can be reopened). One theory as to why this happens posits that many users don't pay attention to some of these warnings. I won't speculate as to the forces at work here, but I would bet that my hypothesis that most closed questions are not reopened isn't the fault of the reviewers, but the askers.
That said, the asked of this question did an admirable job of working to improve the question, so kudos to him for that. I do hope that the question is reopened.
My second and final point (I think) is that I think you over-reacted. I specifically dislike the line in your question that goes
I have no desire to participate in or to be associated with a community that ostracizes young people who are sincerely trying to learn physics.
I think I qualify as a young person (16 years old), and I've found no such issues here.1 My first posts on Physics Stack Exchange were a bit . . . naïve, I suppose - well, my questions were. But even though my questions weren't the best, nobody tried to kick me off. I was far from an expert, and I'm still very, far away from being one. Yet my experience has been quite good. Was I lucky? I don't think so. I've know others who have had essentially the same experience that I had.
I don't know what you've seen in the past, as I guess from allusions in your question that you deleted a previous account. But I think that you overreacted to what happened. The user in question was not bullied nor ostracized. Please don't leave the site because of something minor like this. Experts like you are the key to making Physics Stack Exchange as good a site as it is.
I actually do have an unrelated third point, by the way. On a technical note, reviewers cannot be pinged in comments (see this Meta answer). Perhaps that should be a new feature-request, but at the moment, you'll have to contact reviewers in chat.
1 The question has now been reopened.
2 I also agree with a comment by Zach466920 (just to give some support from a similar user).