Q1. A crate of 31.9- tools rests on a horizontal floor. You exert a gradually increasing horizontal push on it and observe that the crate just begins to move while your force exceeds 345. After that you must reduce your push to 247 to keep it moving at a steady 29.0.

Q2. Consider a system of two bound particles (e.g., two nucleons bound by the weak force), of spins S1, S2, with s1 = s2 = 1/2. In an external magnetic field, the interaction Hamiltonian is H = µB • S, with S = (S1 + S2). A random distribution (containing particles of all possible wave functions) of these systems is passed during a Stern-Gerlach apparatus with B = (-ax, 0, Bo+ az), with |Bo| >> |az| and |Bo|>> |ax|. The deflected beams are discarded. What would be the result of a measurement of S^2 on the surviving states? Give details.

(1) 0 for all of them

(2) 2 hbar^2 for all of them

(3) none of above (explain)