# $u=(3/2)nRT$ when $T=0$

Why does a body with $$0\ K$$ temperate does the internal energy NOT become $$0\ J$$? My lecturer said it had to do with some quantum mechanics, but I never really got any answers from him. I really want to understand this to better understand thermal physics.

$$\Delta x \Delta p \geq \frac{\hbar}{4\pi}$$