# Formula Symbols - P

Written by Jerry Ratzlaff on . Posted in Nomenclature & Symbols for Engineering, Mathematics, and Science

## Formula Symbols - P

For other symbols see:  A - B - C - D - E - F - G - H - I - J - K - L - M - N - O - P - Q - R - S - T - U - V - W - X - Y - Z

SymbolGreek SymbolDefinitionUSMetric
$$\partial$$ partial partial derivative - -
$$\rho_p$$ rho particle density $$lb\;/\;ft^3$$ $$kg\;/\;m^3$$
$$R \;or\; r$$ - particle position vector - -
$$Pe$$ - Peclet number dimensionless number dimensionless number
$$P$$ - perimeter $$ft$$ $$m$$
$$T$$ - period - -
$$T$$ - periodic time - -
$$PF$$ - performance factor - -
$$PN$$ - performance number - -
$$\mu$$ mu permeability  $$ft^2$$ $$m^2$$
$$\mu_o$$ mu permeability of vacuum constant constant
$$\epsilon$$ epsilon permittivity - $$F\;/\;m$$
$$\epsilon_o$$ epsilon permittivity of vacuum constant constant
$$\gamma$$ gamma photon - -
$$\pi$$ pi Pi dimensionless number dimensionless number
$$d$$ - pipe inside diameter ID $$in$$ $$mm$$
$$W_p$$ - pipe weight $$lb\;/\;ft$$ $$kg\;/\;m$$
$$F_p$$ - piping geometry factor dimensionless number dimensionless number
$$PDV$$ - piston deck volume $$in^3$$ $$cc^3$$
$$Pl \;or\; h$$ - Planck constant constant constant
$$Y$$ - Planck function constant constant
$$l_p$$ - Planck length constant constant
$$m_p$$ - Planck mass constant constant
$$t_l$$ - Planck time constant constant
$$\alpha \;or\; \beta \;or\; \gamma \;or\; \theta \;or\; \phi$$ alpha , beta , gamma , theta , phi plane angle $$deg$$ $$rad$$
$$p$$ - plasma pressure - -
$$Z$$ - plastic section modulus of a steel beam $$in^2$$ $$mm^2$$
$$b$$ - plate long side dimension $$ft$$ $$m$$
$$a$$ - plate short side dimension $$ft$$ $$m$$
$$O$$ - point of origin - -
$$Po \;or\; \mu \;or\; \nu$$ mu , nu Poisson's Ratio - -
$$J$$ - polar area moment of inertia $$ft^4$$ $$m^4$$
$$e$$ - polarization vector - -
$$n$$ - polytropic exponent - -
$$J$$ - polar moment of inertia $$in^4$$ $$m^4$$
$$P \;or\; \phi$$ phi porosity percent percent
$$x$$ - position - -
$$x_d \;or\; \Delta x$$ Delta position differential - -
$$U \;or\; V$$ - potential difference - -
$$PE \;or\; E_p$$ - potential energy $$ft-lbf$$ $$J$$
$$P$$ - power $$lbf\;/\;sec$$ $$W$$
$$P$$ - power $$HP$$ $$W$$
$$P$$ - power $$Btu \;/\; sec$$ $$kW$$
$$pf$$ - power factor dimensionless number dimensionless number
$$W$$ - power jack load $$lbf$$ $$N$$
$$N_p$$ - Power number dimensionless number dimensionless number
$$PTR$$ - power-to-heat ratio - -
$$Pr$$ - Prandtl number dimensionless number dimensionless number
$$P \;or\; p$$ - pressure $$lb\;/\;in^2 \;or\; psi$$ $$Pa$$
$$\phi$$ - pressure angle $$deg$$ $$deg$$
$$C_p \;or\; \beta$$ beta pressure coefficient dimensionless number dimensionless number
$$p_d \;or\; \Delta p$$ Delta pressure differential $$lb\;/\;in^2 \;or\; psi$$ $$Pa$$
$$x_T$$ - pressure differential ratio factor $$lb\;/\;in^2 \;or\; psi$$ $$Pa$$
$$PG$$ - pressure gradient $$psi\;/\;ft$$ $$kPa\;/\;m$$
$$p_{inc}$$ - pressure increase $$lb\;/\;in^2 \;or\; psi$$ $$Pa$$
$$F_L$$ - pressure recovery factor - -
$$\alpha$$ alpha pressure wave velocity $$lb\;/\;in^2 \;or\; psi$$ $$Pa$$
$$S$$ - probability current density - -
$$P$$ - probability density - -
$$\propto$$ propto proportional to - -
$$p$$ - proton - -
$$\eta$$ eta pulley efficiency - -
$$\epsilon$$ epsilon pulley loss factor - -