The Viscous Model

In this exercise you will further test the viscous model by comparing it with the motions of cups of different masses. A good model should match the motions of lighter and heavier cups (using identical force functions and parameters) as well as it matches the mass 5 cup. (Note that there may be slight variations in initial velocity due to release times.)

Double-click the green arrow to open the video in Tracker. Note that the video has already been calibrated.

Click on the Tracker tab with your viscous model from the previous Dynamic Modeling exercise (you may need to reopen the data file that you saved) . Select the viscous model track by clicking on it, then copy it to the clipboard using the Edit|Copy menu item. Then c lick again on the newly opened "CupClipsViscous" tab and paste a copy of the model using the Edit|Paste menu item. Change its name to "mass 5." Then paste twice more, assigning names "mass 8" and "mass 1".

Set the correct masses of the mass 1 and 8 models on the toolbar. Then, for each, open the model inspector by choosing "Model" in its track menu. Adjust the initial values for correct placement and best fit. Note: do not change the parameters or force functions!

Can you get the viscous force model to match the motions of all three cups reasonably well?