# Study Session 3: Quantum Concepts I

What does the Heisenberg uncertainty principle state? What are the implications of the Heisenberg uncertainty principle?

Given the operators $$\hat x=x$$, and $$\hat p_x=-i\hbar\frac{d}{dx}$$, do these operators commute with each other?

When operators commute it implies that their eigenvalues can be measured simultaneously. Considering this, how does your answer for question 2. relate to the Heisenberg uncertainty principle?​​

If two linear operators $$\hat A$$ and $$\hat B$$ share the same eigenfunctions, will these two operators commute?

Why is the de Broglie wavelength of a baseball inconsequential?

How big is big?

a. How large does a particle need to be for it to behave clasically all the time?

b. How large does a box need to be for a quantum mechanical particle to appear free?