1. The problem statement, all variables and given/known data At time t=0 free particle is found in state psi=const*sin(3x)*exp[i(5y+z)]. What values for energy and for momentum we can get if we measure them at t=0 and with what probability? 2. Relevant equations Well, we know that eigenvalues of energy and momentum operator for free particle are (hbar*k)^2/(2m) and hbar*k respectively. 3. The attempt at a solution So, does measured momentum equal hbar*(0, 5, 1) and energy 13(hbar)^2/m? Is probability 100%? Book hints that we can get different values for momentum, not just one I stated before. How is it possible?