Articles on Physics and Simulations
Realistic 2-D Collision Simulation
This Java application simulates a realistic collision of spherical objects in a two dimensional space. The calculations for the collision response in this simulator is based on the Newton’s “Conservation of Linear Momentum” theory. This theory said, when a collision occurs in an isolated system, the total momentum of the objects in the system before the collision equals to the total momentum afer the collision”. This theory is used to calculate the velocity of the objects after collision. Certain collisions are called elastic collision, which both momentum and kinetic energy are conserved. In an inelastic collision, the total kinetic energy before and after the collision is not conserved. In a 2-D collision, we also know the fact that only the velocity that is parallel to the collision direction is changed. The velocity that is perpendicular to the collision direction remains unaffected. With these knowledge in mind, we can create a somewhat realsitic simulator that illustrates the collision among spherical objects.
Planet Orbit Simulation
This Java applet simulates the motion of a satellite, orbiting around another planet. You can interactively change the launch velocity of the satellite to explore different orbital path that it will produce. The motion of the satellite is calculated as accurate as possible using Newton’s Law of Motion and Newton’s Law of Gravitation. The applet can even automatically calculates the launch velocity of the satellite that will produce a circular orbit based on its current position. The calculation is done based on Kepler’s Law. The small motion of the central planet is neglected in this applet. I developed this Javaapplet mainly to learn and explore the pattern of an orbiting mass around a central body in a more interesting and interactive manner.