angular momentum


Definition of angular momentum

: a vector quantity that is a measure of the rotational momentum of a rotating body or system, that is equal in classical physics to the product of the angular velocity of the body or system and its moment of inertia with respect to the rotation axis, and that is directed along the rotation axis

Examples of angular momentum in a Sentence

Recent Examples on the Web Think back to the vaguely familiar high school science terms of centripetal force and angular momentum. Jeff Berardelli, CBS News, "Hurricane Delta bears striking resemblance to Wilma, the Atlantic's most intense hurricane on record," 8 Oct. 2020 Finally, the angular momentum is too great for the star's gravity to attract the matter in any closer. Sarah Lewin Frasier, Scientific American, "Astronomers Spy Dusty "Traffic Jam" in Young Star System," 14 Feb. 2017 If the atom were to start rotating, then something else has to provide the angular momentum. Chris Lee, Ars Technica, "Atoms spin backward while flying along a surface," 23 Sep. 2019 In the quantum world, this can only happen if electrons or photons carry away or deliver some angular momentum. Chris Lee, Ars Technica, "Atoms spin backward while flying along a surface," 23 Sep. 2019 The puck rockets toward the goal as the player converts angular momentum (stick and torso swing) to linear momentum (the puck traveling a straight course for the goal). Anchorage Daily News, "The physics of slapshots and mid-ice collisions," 8 Feb. 2020 These particles’ lack of angular momentum means that fewer symmetries restrict their interactions. Quanta Magazine, "Why the Laws of Physics Are Inevitable," 9 Dec. 2019 Their impressive degree of stability is enforced by the approximate conservation of energy and angular momentum. Frank Wilczek, Scientific American, "The Exquisite Precision of Time Crystals," 16 Oct. 2019 It might be described with just its mass, angular momentum and charge. Quanta Magazine, "Are We All Wrong About Black Holes?," 10 Sep. 2019

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'angular momentum.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

See More

First Known Use of angular momentum

1817, in the meaning defined above

Keep scrolling for more

Learn More about angular momentum

Time Traveler for angular momentum

Time Traveler

The first known use of angular momentum was in 1817

See more words from the same year

Statistics for angular momentum

Cite this Entry

“Angular momentum.” Dictionary, Merriam-Webster, Accessed 22 Jan. 2021.

More from Merriam-Webster on angular momentum Encyclopedia article about angular momentum

Comments on angular momentum

What made you want to look up angular momentum? Please tell us where you read or heard it (including the quote, if possible).


Test Your Vocabulary

Slippery Words Quiz—Changing with the Times

  • ducreux self portrait yawning
  • What is an earlier meaning of nice?
Name That Thing

Test your visual vocabulary with our 10-question challenge!

Universal Daily Crossword

A daily challenge for crossword fanatics.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!