# Thrust (with cross section area)

## Description

Thrust is a reaction force described quantitatively by Newton’s second and third laws. When a system expels or accelerates mass in one direction, the accelerated mass will cause a force of equal magnitude but opposite direction on that system. The force applied on a surface in a direction perpendicular or normal to the surface is called thrust. Force, and thus thrust, is measured in the International System of Units (SI) as the newton (symbol: N), and represents the amount needed to accelerate 1 kilogram of mass at the rate of 1 metre per second squared.

In mechanical engineering, force orthogonal to the main load (such as in parallel helical gears) is referred to as thrust.

Related formulas## Variables

T | thrust (N) |

ρ | density of the fluid (kg/m^{3}) |

A | area of the cross section of the propelled volume of fluid (m^{2}) |

v | wind speed (m/s) |