Hooke's Law & Moduli: Restoring force is $F = -k \Delta x$. Tensile stress $\sigma = F/A$, tensile strain $\epsilon = \Delta L / L_0$, and Young's Modulus $Y = \sigma / \epsilon$.
Surface Tension & Capillary Action: Intermolecular cohesive forces create surface energy $\gamma$. Capillary rise in a tube of radius $r$ is $h = \frac{2\gamma\cos\theta}{\rho g r}$.
Stokes' Law & Viscosity: Drag force on a sphere of radius $r$ in fluid with viscosity $\eta$ is $F_d = 6\pi\eta r v$. Terminal velocity is $v_t = \frac{2r^2(\rho_p - \rho_f)g}{9\eta}$.
Operating Instructions: Switch tabs in the left sidebar to simulate Elastic strain, Surface tension capillary elevation, and fluid Viscosity terminal velocity.