[color=#999999]This activity is from the Spanish [i]GeoGebra book [/i][url=https://www.geogebra.org/m/kxxrwxyg]Cómo se hace... con GeoGebra[/url].[/color][br][br]This construction uses javascript code based on the [url=https://www.geogebra.org/m/kxxrwxyg#material/hhsdk9jz]previous construction[/url], which allows simulating the elastic collision of several circles or "bubbles". At all times we can:[br][list][*]Change the positions of the bubbles. Just drag the desired bubble.[/*][/list][list][*]Show or hide velocity vectors.[br][/*][/list][list][*]Change the length and direction of their velocities. To do this, it is recommended to stop the animation (clicking on the almost invisible Play/Stop button, in the bottom left corner of the graphical view) momentarily and move the arrowheads (velocity vectors) as desired.[br][/*][/list][list][*]Change the number of bubbles, up to a maximum of 20.[br][/*][/list][list][*]Change the radius of the bubbles, up to a maximum of 2 units.[br][/*][/list][list][*]Change the speed of the animation.[br][/*][/list][br]Due to the limited space of the stage and the respective speeds of bubbles, it is recommended to use an animation speed not too high, as well as seeking a balance between the number of bubbles and the radius of each one. Otherwise, they may appear temporarily undue overlaps.[br][br]Note that the total kinetic energy [math]\frac{1}{2}m_1v_1^2+\frac{1}{2}m_2v_2^2+...[/math] does not vary as long as we do not vary the number of bubbles or their vectors. Taking the constant amount of 2 units as the mass of each bubble, that energy is [math]v_1^2+v_2^2+...[/math] the result of which appears in the construction.[br][br]You can view a [url=https://www.geogebra.org/m/yq6thwye]3D version[/url] of this activity.

[color=#999999]Author of the GeoGebra activity and construction: [url=https://www.geogebra.org/u/rafael]Rafael Losada[/url].[/color]