|
Rate of Change of Angular Momentum |
 |
 |
 |
|
Written by supaktra
|
|
Monday, 02 April 2012 12:37 |
|
ที่มา : www.youtube.com Upload by MIT
In this lecture, Professor Lewin covers the rate of change in angular momentum through the use of rolling motion and gyroscopes. When you apply a torque to a fast spinning wheel, it moves the spin angular momentum in the direction of the torque (torque is a vector). This is called precession. A suitcase is brought in that requires special handling. There is a fast rotating flywheel inside! A student volunteers to carry the suitcase around. The suitcase behaves in a weird manner as the student turns around.
|
|
|
Doppler Shift and Stellar Dynamics |
|
|
|
|
Written by supaktra
|
|
Monday, 02 April 2012 12:34 |
|
ที่มา : www.youtube.com Upload by MIT
Doppler Effect, Binary Stars, Neutron Stars and Black Holes. Doppler shift is introduced with sound waves, then extended to electromagnetic waves (radiation). The Doppler shift of stellar spectral lines and/or pulsar frequencies provides a measure of the line-of-sight (so-called radial) velocity of the source relative to the observer. Combined with Newton's law of universal gravitation, this can lead to the orbital parameters and the mass of both stars in a binary star system.
|
|
Torques, Oscillating Bodies |
|
|
|
|
Written by supaktra
|
|
Monday, 02 April 2012 12:25 |
|
มี่มา : www.youtube.com Upload by MIT
In the absence of a net external torque on an object, angular momentum is conserved. When an object oscillates about an axis of rotation, there is a variable restoring torque acting on the object. A review is given of equations for angular momentum and torque, and the importance of choosing the point of origin. These equations are exercised using an example of a circular orbit.
|
|
|
Written by supaktra
|
|
Monday, 02 April 2012 12:29 |
|
ที่มา : www.youtube.com Upload by MIT
Kepler's Laws, Elliptical Orbits, Change of Orbits, and the famous passing of a Ham Sandwich by astronauts in orbit. Kepler's three Laws summarize the motion of the planets in our solar system. Following Newton's law of universal gravitation, the conservation of angular momentum and mechanical energy allow us to calculate the semimajor axis of the elliptical orbits, the orbital period and other orbital parameters. All we have to know is one position and the associated velocity of a planet and the entire orbit follows.
|
|
Written by supaktra
|
|
Monday, 02 April 2012 12:22 |
|
ที่มา : www.youtube.com Upload by MIT
Angular momentum (a vector) is introduced. The rate of change of angular momentum is related to the torque (also a vector). In the absence of an external torque, angular momentum is conserved. Spin angular momentum (of planets, stars, neutron stars) is also discussed.
|
|
|
|
|
|
|
Page 18 of 30 |
Feed Entries
