What IS Angular Momentum?

Minute Physics provides an energetic and entertaining view of old and new problems in physics -- all in a minute!

 

How do figure skaters exploit Newtonian physics when they spin?

Legendary MIT physics professor Walter Lewin describes some of the science that was in action during the Winter Olympics in Sochi. He explains how ice-skaters use their arms to moderate their moment of inertia, which in turn affects the angular velocity of their spins. The biomechanics is fairly straightforward, but Walter Lewin always manages to make his lessons engaging thanks to his trademark charisma.

 

The Cubli: a cube that can jump up, balance, and 'walk'

The Cubli is a 15 × 15 × 15 cm cube that can jump up and balance on its corner. Reaction wheels mounted on three faces of the cube rotate at high angular velocities and then brake suddenly, causing the Cubli to jump up. Once the Cubli has almost reached the corner stand up position, controlled motor torques are applied to make it balance on its corner. In addition to balancing, the motor torques can also be used to achieve a controlled fall such that the Cubli can be commanded to fall in any arbitrary direction. Combining these three abilities -- jumping up, balancing, and controlled falling -- the Cubli is able to 'walk'.

 Lead Researchers: Gajamohan Mohanarajah and Raffaello D'Andrea This work was done at the Institute for Dynamic Systems and Control, ETH Zurich, Switzerland and was funded in part by the Swiss National Science Foundation (SNSF), grant number 146717.

 For more details visit: http://www.idsc.ethz.ch/Research_DAndrea/Cubli

 

Jabulani Football Physics - Sixty Symbols

We discuss the Jabulani (official World Cup football) which has caused so much debate - and a few of our scientists take it for some field testing!

 

Out scientists field test the official World Cup football with an impromptu penalty shoot-out.

Gyroscopes Made Easy

The motion of a gyroscope in response to an applied force is analyzed. TSG's gimbaled gyroscope is used to demonstrate.

 

What on Earth is spin? - Brian Jones

View full lesson: http://ed.ted.com/lessons/what-on-earth-is-spin-brian-jones

Why does the Earth spin? Does a basketball falling from a spinning merry-go-round fall in a curve, as it appears to, or in a straight line? How can speed be manipulated while spinning? In short, why is the spinning motion so special? Brian Jones details the dizzyingly wide array of ways that spinning affects our lives.

 Lesson by Brian Jones, animation by Flaming Medusa Studios.

 

Hewitt-Drew-it! 43. Angular Momentum

Conservation of angular momentum, with examples, including Paul in the classroom, are examined.

Other Hewitt-Drew-it! videos

 

Wobbly Earth - Sixty Symbols

Axial precession is the reason the Earth's axis has a long-term but quite dramatic "wobble", as explained here by Roger Bowley and Mike Merrifield.

Other Sixty Symbols videos

 

ScienceCasts: Christmas Sky Show

The Moon and Jupiter are converging for a heavenly sky show on Christmas 2012. Got a telescope? Something extra-special is happening on Jupiter that makes it an appealing target for backyard optics.

 

How Does A Boomerang Work?

A boomerang can execute its unique roundtrip flight by making use of three fundamental physics principles: lift, relative velocity, and gyroscopic precession.

Other Veritasium videos

Angular Momentum - Sixty Symbols

A rather dizzy Professor Bowley sacrifices his well-being in the name of science.

Other Sixty Symbols videos

MIT 8.01 Classical Mechanics Lecture 24

MIT Physics Course

Professor Walter Lewin

8.01 Physics  I: Classical Mechanics, Fall 1999

Rolling motions, gyroscopes

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MIT 8.01 Classical Mechanics Lecture 21

MIT Physics Course

Professor Walter Lewin

8.01 Physics  I: Classical Mechanics, Fall 1999

Torques - Oscillating Bodies - Hoops

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Gyroscope in space

Here's a nice demonstration in the international space station.

Gyroscope

Gyroscope:  experiments and applications.