Some of us have talked earlier about the problem of the big four kinematics equations. In the text for my intro physics class, students are given these four equations:
Anyway, the strategy students are told is to select an equation that both has the variable they are looking for and has the other variables they do know. I sat down and thought about the logic of this approach for a while, and decided that if we really think this is what is best for students (which I don’t), we should also give them this equation:
Yes, of course, it’s ridiculous. But giving them this fifth equation is no more ridiculous that giving them the four above either. In fact, giving them the fifth at least completes the absurdity to its logical conclusion. And I’m all for that. See, given six variables, you need five equations to relate each one. Now, students will never have to worry about having to use two equations.
Take that algebra-based physics!