Physics Marathon (Solve a Problem and Post Your Own)

[Phys student]

I saw this idea on another forum and I though it'd be fun if it was employed here, a marathon works as follows:

1. One person posts a problem.
2. Then another person solves it and then posts another problem.
3. Another person comes and solves the second problem and then posts another problem.

I suggest we keep the problems limited to classical topics. But, this is isn't a rule of course.

I'll start:

Problem 1:

The sign shown below (See attached photo) consists of two uniform legs attached by a frictionless hinge. The coefficient of friction between the ground and the legs is μ. What is the maximum value of θ such that the sign will not collapse?

 

[Khashishi]

But how can we tell if it's a homework problem?

 

[Phys student]

But how can we tell if it's a homework problem?

Well, we can tell if a problem requires thinking and not just routine textbook problem solving. As for my problem, it's definitely not a homework problem (it's actually from an Olympiad).

 

[berkeman]

Yeah, but we may not be able to allow a thread like this, because it could be used by some students to cheat. Let me run it by the other Mentors...

 

[berkeman]

After a discussion among the Mentors, we agree that a thread like this would be very difficult to Moderate, since it would be easy for students to post their homework problems disguised as Marathon questions. Sorry, this thread will stay closed.