Kinetic friction

Input(s)

$\mu_{\mathrm{s}}$: Static Viscosity $(\mathrm{cP})$

a: Constant of Friction in X Direction (dimensionless)

$\mathrm{g}$: Acceleration Due to Gravity $\left(\mathrm{ft} / \mathrm{s}^{2}\right)$

Output(s)

$\varphi$: Angle of Friction (rad)

$\mu_{\mathrm{k}}$: Kinetic Viscosity (cP)

Formula(s)

$$ \begin{gathered} \varphi=\tan \left(\mu_{\mathrm{s}}\right) \\ \mu_{\mathrm{k}}=\mu_{\mathrm{s}}-\left(\frac{\mathrm{a}}{\mathrm{g} * \sin (\varphi)}\right) \end{gathered} $$

Reference(s)

Samuel. E Robello. 501 Solved Problems and Calculations for Drilling Operations. Sigma Quadrant. 2015. Houston, Texas, Page: 375.