In physics, angular momentum (rarely, moment of momentum or rotational momentum) is the rotational analog of linear momentum. It is an important quantity in physics because it is a conserved quantity—the total angular momentum of a closed system remains constant. Motorcycles, frisbees[1] and rifled bullets all owe their useful properties to conservation of angular momentum. Conservation of angular momentum is also why hurricanes and galaxies have spirals.
Angular momentum in nature and the cosmos edit
Tropical cyclones and other related weather phenomena involve conservation of angular momentum in order to explain the dynamics. Winds revolve slowly around low pressure systems, mainly due to the coriolis effect. If the low pressure intensifies and the slowly circulating air is drawn toward the center, the molecules must speed up in order to conserve angular momentum. By the time they reach the center, the speeds become destructive.[2]
Johannes Kepler determined the laws of planetary motion without knowledge of conservation of momentum. However not long after his discovery their derivation was determined from conservation of angular momentum. Planets move more slowly the further they are out in their elliptical orbits, which is explained intuitively by the fact that orbital angular momentum is proportional to the radius of the orbit. Since the mass does not change and the angular momentum is conserved, the velocity drops.
Tidal acceleration is an effect of the tidal forces between an orbiting natural satellite (e.g. the Moon) and the primary planet that it orbits (e.g. Earth). The gravitational torque between the Moon and the tidal bulge of Earth causes the Moon to be constantly promoted to a slightly higher orbit and Earth to be decelerated in its rotation. The Earth loses angular momentum which is transferred to the Moon such that the overall angular momentum is conserved.
Angular momentum in human culture edit
Angular momentum in engineering and technology edit
Engine flywheel
lawnmower flywheel
Inertial navigation system Bicycle Gyroscopic stablization Rifled bullets Circular saw
Angular momentum in sports and dance edit
sports
diving
figure skating
football
baseball soccer billiards frisbees
Draft articles edit
User:LaurentianShield/sandbox/Wisconsin Department of Financial Institutions
Education of a Coach edit
Some reference links:
- New York Times review
- Entertainment Weekly review
- Review in Publisher's weekly
- Australian Sports Commission review This review article adds a lot of credibility to the subjective assertion that Belichick is one of the greatest NFL coaches of all time, since the article is written for an Australian government program.
George Coulter edit
George Coulter is the namesake of Coulterville, California]. He was a merchant serving the gold miners, but eventually moved into the business of servicing the tourist trade to Yosemite Valley. He built a trail and ultimately a road into the park, the first northern route into the valley. He was one of the first park commissioners. He owned a hotel in the park.
His wife was Anna Margaret Coulter. They were married on June 16, 1840. They came overland to California in 1849.
Coulter died January 4, 1902.
This is a test.[3]
References edit
- ^ "Soaring Science: The Aerodynamics of Flying a Frisbee". Scientific American. August 9, 2012. Retrieved January 4, 2022.
- ^ "Tropical Cyclone Structure". National Weather Service. Retrieved January 4, 2022.
- ^ This is a test of the reference tag pair.
A Volume of Memoirs and Genealogy of Representative Citizens of Northern California. Chicago: Standard Genealogical Publishing Company. 1901. p. 608=610. Retrieved December 4, 2013.
Quotes from Huntley's book edit
From Huntley's book George Coulter: scan 121 & 122 (forgot to do!!) p. 129: Many of the historians who have uncritically accepted the perspective of the Yosemite Commissioners have gone further to make sweeping statements on behalf of the unknown "gentlemen of taste" who originated the grant idea in 1864. Hans Huth adamantly declares, without evidence, that in writing to Conness, Israel Ward Raymond "certainly did not take this step to further any of his business interests." [footnote 37] Huntley then mentions Coulter in this context