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ME 163 QuickTime Movies |
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This page gives access to the QuickTime movies that were presented as classroom demos. If you have Quicktime installed in your computer (preferably version 4), then you will be able to view a movie by clicking on its title in the list below.
Fit of logistic model to US Population. This movie shows a fit of the US population data from 1790 to 1920 with a logistic model. The parameter being varied is the maximum sustainable population, called PM on the graphs. The best fit is for a PM around 220 (million).
Cyclic Heating and Cooling of a Building. This movie shows the variation of interior temperature in a building subjected to a periodic external temperature. The parameter varied in the movie is the building time constant 1/k. The minimum and maximum allowed building temperatures are shown in blue and red respectively, and the external temperature is dashed. As the building time constant increases (more insulation), the variation in interior temperature decreases. Try to find the minimum time constant for which the interior temperature is in the allowed range.
Damping Sequence. This movie shows how the time response of a linear damped unforced oscillator varies with the damping parameter zeta, defined in the standard way as the damping constant b divided by twice the square root of (mass times spring constant). All graphs show the critically damped response in red, and the response for the current zeta in blue.
Resonance. This movie shows the amplitude response of a linear oscillator to sinusoidal forcing. Each frame of the movie shows the response Ap versus driver frequency gamma. Successive frames correspond to increasing values of the damping parameter zeta, which runs from zeta = 0.01 at the beginning of the movie to 1.0 at the end of the movie. The amplitude Ap is scaled by the static deflection at the same force amplitude, and the driver frequency is scaled by the natural frequency of the undamped system.
Nonlinear Vibration. This movie shows solutions of Duffing's equation. This version of Duffing's equation describes an undamped oscillator with a cubic nonlinearity in the spring force, as an addition to the linear spring force. The movie shows a succession of solutions, each with a larger initial amplitude and all with zero initial velocity. Each plot shows the time dependent amplitude scaled by the initial amplitude. As the movie progresses through larger initial amplitudes, one can see that the period of the motion decreases. This dependence of period on amplitude is one of the hallmarks of nonlinear vibrations.