Editing Thrust (section)

== Examples ==
A [[fixed-wing aircraft]] propulsion system generates forward thrust when air is pushed in the direction opposite to flight. This can be done by different means such as the spinning blades of a [[Propeller (aircraft)|propeller]], the propelling jet of a [[jet engine]], or by ejecting hot gases from a [[rocket engine]].<ref>{{cite web|url=https://www.grc.nasa.gov/WWW/k-12/airplane/newton3.html|title=Newton's Third Law of Motion|website=www.grc.nasa.gov|access-date=2 April 2020|archive-url=https://web.archive.org/web/20200203022807/https://www.grc.nasa.gov/WWW/K-12/airplane/newton3.html|archive-date=3 February 2020|url-status=live}}</ref> Reverse thrust can be generated to aid braking after landing by reversing the pitch of variable-pitch propeller blades, or using a [[Thrust reversal|thrust reverser]] on a jet engine. [[Rotary wing aircraft]] use rotors and [[thrust vectoring]] [[V/STOL]] aircraft use propellers or engine thrust to support the weight of the aircraft and to provide forward propulsion.

A [[motorboat]] propeller generates thrust when it rotates and forces water backwards.

A [[rocket]] is propelled forward by a thrust equal in magnitude, but opposite in direction, to the time-rate of momentum change of the [[exhaust gas]] accelerated from the combustion chamber through the rocket engine nozzle. This is the [[exhaust velocity]] with respect to the rocket, times the time-rate at which the mass is expelled, or in mathematical terms:
:<math>\mathbf{T}=\mathbf{v}\frac{\mathrm{d}m}{\mathrm{d}t}</math>
Where '''T''' is the thrust generated (force), <math>\frac {\mathrm{d}m} {\mathrm{d}t}</math> is the rate of change of mass with respect to time (mass flow rate of exhaust), and '''v''' is the velocity of the exhaust gases measured relative to the rocket.

For vertical launch of a rocket the initial thrust at [[wikt:liftoff|liftoff]] must be more than the weight.

Each of the three [[Space Shuttle Main Engine]]s could produce a thrust of 1.8&nbsp;[[meganewton]], and each of the Space Shuttle's two [[Space Shuttle Solid Rocket Booster|Solid Rocket Boosters]] {{convert|14.7|MN|lbf|abbr=on|lk=on}}, together 29.4&nbsp;MN.<ref>{{cite web|url=http://www.braeunig.us/space/specs/shuttle.htm|title=Space Launchers - Space Shuttle|website=www.braeunig.us|access-date=16 February 2018|archive-url=https://web.archive.org/web/20180406061909/http://www.braeunig.us/space/specs/shuttle.htm|archive-date=6 April 2018|url-status=live}}</ref>

By contrast, the [[Simplified Aid for EVA Rescue]] (SAFER) has 24 thrusters of {{convert|3.56|N|lbf|abbr=on}} each.<ref>{{Cite journal |last1=Handley |first1=Patrick M. |last2=Hess |first2=Ronald A. |last3=Robinson |first3=Stephen K. |date=2018-02-01 |title=Descriptive Pilot Model for the NASA Simplified Aid for Extravehicular Activity Rescue |url=https://arc.aiaa.org/doi/10.2514/1.G003131 |journal=Journal of Guidance, Control, and Dynamics |volume=41 |issue=2 |pages=515–518 |doi=10.2514/1.G003131 |bibcode=2018JGCD...41..515H |issn=0731-5090}}</ref>

In the air-breathing category, the AMT-USA AT-180 jet engine developed for [[radio-controlled aircraft]] produce 90&nbsp;N (20 [[Pound-force|lbf]]) of thrust.<ref>{{cite web
| url = http://usamt.com/Mel/comm/comm_products.html
| title = AMT-USA jet engine product information
| access-date = 13 December 2006
| archive-url = https://web.archive.org/web/20061110025303/http://usamt.com/Mel/comm/comm_products.html
| archive-date = 10 November 2006
| url-status = dead
}}</ref> The [[General Electric GE90|GE90]]-115B engine fitted on the [[Boeing 777]]-300ER has a thrust of 569&nbsp;kN (127,900&nbsp;lbf). It was recognized by ''[[Guinness World Records]]'' as the "World's Most Powerful Commercial Jet Engine"  until it was surpassed by the [[General Electric GE9X|GE9X]] (fitted on the upcoming [[Boeing 777X]]), with 609 kN (134,300 lbf).