The center orange disk is a heavy charged body like an atomic nucleus. The twenty green dots which are located in the left side of the screen are charged particles like alpha particles. The orange body and green particles have the same kind of charge and repel each other by Coulomb force.
First, click the start button. The green particles start moving and are scattered by the orange body. You can change the speed of green particles by scrollbar. If you drag the pointer near the orange body, you can change the radius of the body without changing the amount of the charge.
Next, check the Strobo checkbox. You can see the orbit line of the green particles. The orbit line can erase by clicking Start or Reset button. If you click the Reset button, you can set the state initial.

Please try to check the following points.

(1)How dose the situation change if you increase the speed of the green particles?
(2)How dose the situation change if you increase the radius of the orange body?
(3)How should we set the conditions if we want to know the radius of the orange body?

This simulation is the same situation of Rutherford's experiment.
This motion is calculated by 4th order Runge-Kutta method.

Copyright 1997 KATO Noriyoshi

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