This isn't homework...I'm reviewing physics after many years of neglect.

Given 2 masses,

, connected by a rigid, massless rod, stationary with respect to a ramp which makes an angle of

with the horizontal, with coefficients of static friction between the masses and the ramp =

respectively, what is the magnitude of the tension or compression in the rod, and what are the magnitudes of the static friction,

, acting on each mass?

This assumes

is small enough that the masses do not lose traction, i.e.,

Note that if the masses are assumed to already be moving, then the problem is straightforward:

Where T is the tension in the rod (T<0 implies compression). Such problems are common in basic physics, e.g., Halliday, Resnick, & Krane, 4th Ed., chap.6, problem 29.

So I assumed it would be straightforward to do the same problem, but with the masses stationary. But I get 2 equations (sum of the forces for each mass) and 3 unknowns (T,

).

I find it surprising that such a simple situation is undetermined, and assume I've missed something simple.

Note: I've looked through several physics texts and can find only problems in which the masses are already moving.

Also, it's driving me crazy!