Hooke's law

 $$\boldsymbol{\sigma}\propto \nabla\textbf{F}$$

Latent heat

 $$\rho L=\frac{1}{2}Y\langle\epsilon^2\rangle$$

Quantum thrust and Rotckets

 $$T=v\frac{dm}{dt}$$

$$E=\hbar\omega, \ E=mc^2$$

$$T=\frac{\hbar}{c}\dot{\omega}$$