Use an online tutorial to learn the cocos2d system. Cocos2d is a set of tools for Objective C, it includes Box2d which is a physics engine that I am planning on using to power my simulations.
Design a paper prototype for my app
Use box2d to make a test pendulum to make sure it is the best platform for the job
Testing on a read iDevice will allow for more useful feedback on how the app performs. It will give accurate speed tests and will show how the software actually reacts with the touch input.
This step also includes the changes that will be made to the code to make it work more properly on the iPad
Check the pendulum for many values to make sure it is accurate/ make it responsive and make changing variables user friendly.
Allow users the test the almost finished app. I purposely put this step just before the polishing stage, because changes will be easier to implement with less time lost.
hydraulics, buoyancy, spring/mass system