teaching - Is it reasonable for a professor to ask students to stay 30-45 minutes past scheduled class time every week?

I'm currently in a class in my major that meets for 50 minutes 3 times a week. Meanwhile, I'm a member of a campus club, unrelated to my major, which meets right after this class one day.

My professor has decided that he should have the students stay an extra 30-45 minutes after class on the day of the meetings so that he can continue to teach.

I'm the only one in the class who has voted against this, which makes me uncomfortable, because I'm what's forcing the class to have a faster pace.

Am I right in being outraged? Is it not the professor's job to teach the necessary course material in the time allotted, as opposed to having students stay late for no credit? Should I cave in and just not go to the club meetings? They're not important for my major, and I'm not an officer, but I immensely enjoy them.

Edit: I've been asked in the comments why my professor is doing this. It has to do with the pacing of the course--if we had to stick to 50 minutes 3 times a week, then the pace would have to be much faster.

Answer

I guess I'm going to be the contrary opinion here. I don't think your professor's request is reasonable at all. Class time is scheduled the way it is so that people can plan the rest of their lives around the schedule. In this case, nobody but you seems to have anything from 12:50 on, but that shouldn't encourage the prof to monopolize that time.

Some may think your extracurricular activity is trivial or that you should skip it, but that math club could easily have been another class or your job. The professor is in a position of power, and he should respect his position by not trying to compel you to work outside the system because it's convenient to him. Several of your peers may actually appreciate that you're the lone hold out even if they won't ever admit it.

I would have no problem with the prof offering extra sessions where no required material was covered. This could be extra practice working example problems or a Q&A session to clear up anything confusing from class. That being said, I think professors should be held to teaching the required stuff in the allotted time.