A simple question
Here’s a question that generated a lot of interest among the people involved in my metals and superconductors short course.
The question is this: Is Newton’s second law – that the net force on a body is equal to its mass times its acceleration – simply a mathematical definition of what a force is? Or is there some additional physical content? If so, what precisely is that content?
Some people regard the answer to this question as “obvious”. As is often the case with interesting questions, one person’s “obvious” may be another person’s “wrong”, so I’d be interested to hear other people’s opinions. If I have time (very busy the past couple of weeks) I’ll put together my own best understanding of the answer.