revolutions per minute
Học thuậtThân thiện
Definition
Noun 1. A unit of rotational speed: A measurement of how many complete turns or cycles a rotating object makes in one minute. It is a standard unit for expressing the speed of engines, motors, fans, turntables, and other mechanical components.
Usage
- Revolutions per minute is used to quantify the rotational speed of an axle, shaft, disk, or rotor.
- It is commonly abbreviated as rpm or RPM.
- It functions as a noun phrase, often following a number (e.g., 3000 revolutions per minute).
Examples
- The old vinyl record spins at 33 1/3 revolutions per minute.
- A typical car engine idles at around 800 revolutions per minute.
- The technician measured the fan's speed at 1200 rpm.
Advanced Usage
- Technical Specification: RPM is a critical specification for motors and engines, indicating their operating speed and power band.
- The motor's maximum torque is achieved at 2500 revolutions per minute.
- Comparative Analysis: Used to compare the rotational speeds of different devices or under different conditions.
- Drilling at a higher number of revolutions per minute produces a smoother finish on wood.
Variants and Related Words
- rpm / RPM (noun): The standard abbreviation for "revolutions per minute."
- The tachometer shows the engine speed in rpm.
- Rev (noun, informal): A single revolution, especially of an engine. Often used in plural ("revs") to colloquially indicate RPM.
- Give it more revs!
- Rotational Speed (noun): The more general term for which revolutions per minute is a specific unit of measurement.
- Hertz (Hz) (noun): The SI unit of frequency, measured in cycles per second. While related, it is not directly interchangeable with RPM (1 Hz = 60 rpm).
Synonyms
- Rotational frequency (per minute): A more technical synonym.
- Rotational speed: A broader, more general synonym.
Related Phrases
- To rev (up) to [number] rpm (phrasal verb): To increase the engine speed to a specified rotational velocity.
- He revved the engine to 5000 rpm.
- At a constant [number] rpm: Operating without variation in rotational speed.
- The centrifuge must run at a constant 10,000 rpm.
Noun
- rate of revolution of a motor
- the engine was doing 6000 revs