# Formula Symbols - P

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

SymbolGreek SymbolDefinitionUSMetric
$$Pe$$ - Peclet number Dimensionless Number Dimensionless Number
$$P$$ - perimeter $$ft$$ $$m$$
$$PF$$ - performance factor - -
$$\epsilon$$ epsilon permittivity - $$F/m$$
$$\gamma$$ gamma photon - -
$$\pi$$ pi Pi Dimensionless Number Dimensionless Number
$$Pl$$ - Planck's Constant - $$J\cdot s$$
$$Po$$ - Polsson's Ratio - -
$$\upsilon$$ upsilon Poisson's Ratio - -
$$n$$ - polytropic exponent - -
$$J$$ - polar moment of inertia $$in^4$$ $$m^4$$
$$P$$ - porosity - -
$$\Delta x$$ - position differential - -
$$x_d$$ - position differential - -
$$PE$$ - potential energy - -
$$P$$ - power $$ft-lbf/sec$$ $$watt$$
$$pf$$ - power factor Dimensionless Number Dimensionless Number
$$N_p$$ - Power number Dimensionless Number Dimensionless Number
$$PTR$$ - power-to-heat ratio - -
$$Pr$$ - Prandtl number Dimensionless Number Dimensionless Number
$$p$$ - pressure $$lbf/ft^2$$ $$Pa$$
$$C_p$$ - pressure coefficient Dimensionless Number Dimensionless Number
$$\Delta p$$ - pressure differential $$lbf/ft^2$$ $$Pa$$
$$p_d$$ - pressure differential $$lbf/ft^2$$ $$Pa$$
$$p$$ - proton - -
$$\eta$$ eta pulley efficiency - -
$$\epsilon$$ epsilon pulley loss factor - -