As soon as the point of impact moves, you need vector math to figure out where it is, OR as Rob pointed out, use complex bodies so that the parts rotate and you can detect collisions with each individual body.
Your question is interesting however as, if you follow it through and really try to solve it, you’ll find… vector math is the solution. I’ll stop saying it, but that is the kind of question that leads to learning this.
Cheers,
Ed