This is a simulation that models a spring system. More updates will follow along with more control over environment variables.
INSTRUCTIONS:
Double-tap the screen to add a point. Drag a line between two points to create a spring. Tap on a point to change whether it is pinned (red=pinned,gray=free). Rotate your iPhone to change the direction of gravity in the simulation. Doing a zoom-in or zoom-out gesture increases or decreases the force of air resistance.