If there is no net external force acting on a body, then its momentum vector is fixed in space (i.e. moving along a string line). If there is no net torque acting on a revolving body, then its angular momentum vector is fixed in space. When there is net torque, the rate of change of angular momentum is equal to the torque. This simulation shows a spinning body has a kind of gyroscope stability. A tilted top spinning about its symmetry axis with an angular velocity w1 (w1=2.*pi/T1). The spinning axis will simultaneously swing around (precess) with singular frequency w2. w2=(mgr/I w1)

You can toggle view of angular momentum,gravitation force and torque vector. Change the self spinning period and see the change of precession frequency. Change the center of gravity (higher/lower the rotating disk) Change the scale and see the effect of inertia (proportional to r*r), so the precision frequency slower down as you increase the scale.

This simulation was created by Fu-Kwun Hwang, NTNU, Taiwan.

found this is the MPLT14 OSP CD

**Press the Alt key and the left mouse button to drag the applet off the browser and onto the desktop.**This work is licensed under a Creative Commons Attribution 2.5 Taiwan License

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