# Quantum Mechanics Expectation

by roshan2004
Tags: expectation, mechanics, quantum
 P: 139 1. The problem statement, all variables and given/known data 1. Calculate the expectation value  of the momentum of a particle trapped in a one-dimensional box. 2. Find the expectation value of the position of a particle trapped in a box L wide. 2. Relevant equations $$\psi _{n}=\sqrt{\frac{2}{L}}sin \frac{n\pi x}{L}$$ $$=\int \psi^*p_{x}\psi dx$$ $$=\int \psi^*x\psi dx$$ 3. The attempt at a solution I got confused on choosing the limits for both the problems for integrating them. What's the limits I should chose for both the problems.