This simulation shows 5 masses connected by springs and free to move in 2 dimensions.
Students can change parameters in the simulation such as gravity, mass, spring stiffness, and friction (damping) and can drag any mass with the mouse to change the starting position. The red springs can be set to have a different stiffness and length than the other springs.
The math and physics used in this simulation are similar to the 2-D Spring and Double 2-D Spring simulations. However the masses can also collide with the walls; the collision handling is similar to the Colliding Blockssimulation. The only novel bit of math occurs when a mass is pinned against a wall: in that case we add up the net forces on the mass and set the acceleration to zero if necessary.