propulsion
/prəˈpʌlʃn/ (bre, ipa) · /prəˈpʌlʃn/ (ame, ipa) · /prə-ˈpəl-shən/ (ame, mw)
propulsion — noun
1. a physical force that moves an object, such as a vehicle or spacecraft, in a par
a physical force that moves an object, such as a vehicle or spacecraft, in a particular direction
Sana studied how the propulsion of a space shuttle is generated during lift-off.
collocation: propulsion of [vehicle]
Without enough propulsion, the fishing boat could not move against the strong current.
uncountable; modified by 'enough'
The new electric motor provides clean propulsion for small passenger ferries.
Kenji explained that jet propulsion pushes a plane forward by creating a stream of hot gas.
- thrust
more specific; refers to the measurable reaction force from expelling mass, commonly used for rockets and engines
- drive
broader; can refer to mechanical power transfer, not necessarily forward motion
- motive power
formal/technical; refers to the energy source that produces motion
- resistance
the opposing force that works against forward movement, such as drag or friction
文法句型
propulsion + of [something]
adjective + propulsion
用法筆記
Propulsion in this sense is uncountable and typically modified by an energy source or method (jet, rocket, electric). Unlike 'thrust', which refers to a specific reaction force measured in newtons, propulsion is a broader term for any forward-driving force.
常見錯誤
2. the system or method by which an object is driven forward through a medium such
the system or method by which an object is driven forward through a medium such as air or water
The engineers developed a new propulsion system that uses solar power for deep-space missions.
collocation: propulsion system
Iker asked whether magnetic propulsion could replace traditional engines on high-speed trains.
compound noun: magnetic propulsion
Rocket propulsion works by burning fuel and forcing the hot gas out of the back at high speed.
Camila's research focuses on improving the efficiency of electric propulsion for small satellites.
- propulsion system
more explicit; refers to the complete assembly of components that produce motion
- propulsion method
highlights the approach or technique rather than the hardware
- motive system
formal; often used in engineering documents for the power-and-drive arrangement
文法句型
propulsion + system / technology / method
adjective + propulsion
用法筆記
This sense commonly appears in compound nouns describing a technology category — 'propulsion system', 'propulsion method', 'propulsion technology'. In everyday conversation, the simpler word 'engine' is more common than 'propulsion system'.