Question 11: It is easy to create an ellipse using a loop of string and two thumbtacks. The string is first stretched over the thumbtacks which act as foci. The string is then pulled tight using the pencil which can then trace out the ellipse. Assume that you wish to draw an ellipse with a semi-major axis of a = 20 cm and e = 0.5. Using what you have learned earlier in this lab, what would be the appropriate distances for a) the separation of the thumbtacks and b) the length of the string? Please fully explain how you determine these values. Kepler's 2nd Law Use the "clear optional features" button to remove the Ist Law features. . Open the Kepler's 2nd Law tab. Press the "start sweeping" button. Adjust the semimajor axis and animation rate so that the planet moves at a reasonable speed. . Adjust the size of the sweep using the "adjust size" slider. . Click and drag the sweep segment around. Note how the shape of the sweep segment changes, but the area does not. Add more sweeps. Erase all sweeps with the "erase sweeps" button. The "sweep continuously" check box will cause sweeps to be created continuously when sweeping. Test this option. Question 12: Erase all sweeps and create an ellipse with a = 1 AU and e = 0. Set t fractional sweep size to one-twelfth of the period. Drag the sweep segment arou Does its size or shape change? NAAP - Planetary Orbit Simul