The Magnus effects of lift and drag due to high velocity and spin are modeled semi-empirically using published experimental results for varying atmospheric pressure and humidity. The change of spin, velocity, and bounce angle are calculated given known parameters of court-ball coefficients of restitution and friction. Trajectories are initialized by on-screen mouse action which sets initial conditions. Trajectory flight data is animated and saved numerically in a text file window which contains height, speed, angle, and spin before and after net crossing, first bounce, and baseline crossing. Racquet collision simulation shows how initial spin and velocity are produced.
Normal modes are symmetry labeled and displayed on one side of the screen .
Amplitudes and phases of each mode can be tweaked to see the effect on the superimposed motion of the whole molecule being animated on the other side. Amplitudes of individual atoms can be varied too, and the resulting normal mode amplitudes respond accordingly. Amplitudes and phases of each eigenstate can be tweaked to see the effect on the superimposed wave motion while it is being animated . Animated simulation of an ancient and deadly war weapon called the Trebuchet. This fiendishly clever catapult was used to bring down fortified cities from around 1100 AD until about 1450 AD and for hundreds of years was more effective than cannons.