rpm

Thân thiện

The mechanic checks the engine's rpm with a digital tachometer.

Definition

Noun: * Revolutions per minute: A unit of measurement for the frequency of rotation, indicating the number of complete turns (revolutions) a rotating object makes in one minute. It is a standard measure of rotational speed for engines, motors, fans, and other mechanical components.

Usage

"Rpm" is used to quantify and describe the speed at which something spins. It is typically written in lowercase and often follows a number. * It is commonly used when discussing the operational speed of engines and motors. * It can describe the rotational speed of components like hard drives, fans, or wheels.

Examples

• The car's tometer showed the engine was running at 2,500 rpm.
• For optimal fuel efficiency, try to keep the rpm below 3,000 while cruising.
• This drill has a variable speed setting, from 500 to 3,000 rpm.
• The old vinyl record spins at 33 1/3 rpm.

Advanced Usage

• Technical Specifications: "Rpm" is a critical specification in technical data sheets for motors, power tools, and computer hardware (e.g., a 7,200 rpm hard drive).
• Redline: In automotive contexts, the "redline" is the maximum safe rpm for an engine, often marked in red on the tachometer.
  • Example: He pushed the engine past its redline of 7,000 rpm.

Variants and Related Words

• Rev (noun/verb): A common informal shortening of "revolution," often used interchangeably with "rpm" in casual speech about engines (e.g., "The engine was doing 6000 revs"). As a verb, it means to increase the speed of an engine.
• Revolutions per minute: The full, unabbreviated form of "rpm."
• Hz (Hertz): The SI unit for frequency, measured in cycles per second. While related, it is not directly interchangeable with rpm (1 Hz = 60 rpm).

Synonyms

• Rotational speed
• Revolution rate

Related Phrases

• Idle rpm / Idling speed: The rotational speed of an engine when it is running but not under load (e.g., when a vehicle is stationary).
  • Example: After starting the car, let it warm up until the idle rpm drops.
• Rpm range / Band: The spectrum of rotational speeds within which a machine operates effectively.
  • Example: This turbine operates most efficiently in the 10,000 to 15,000 rpm range.

Học thuật

Noun

1. rate of revolution of a motor
   • the engine was doing 6000 revs

Từ đồng nghĩa

• revolutions per minute
• rev