PHY.6:1 - Problem frame

Use this pattern when you can identify physical participants and their interactions, but cannot yet say how their coupled situation will evolve. You may know what is conserved while lacking the law that determines an exchange rate. You may have equations for each part while their connection or initial preparation remains inconsistent.

Start with the consequence you need: an initial response, a trajectory, a transported amount, a settled state or a distribution of outcomes. Choose the participants, exchanges and response laws needed for that consequence. A usable first result is a coupled physical description from which the consequence follows, or an identified missing response or incompatible condition that tells you what to resolve next.

Here a response law relates a physical interaction or change to the conditions on which it depends. A constitutive law is one such relation for a material or component. The method constructs an account from physical balances, response laws and preparation; it works across physical branches.

You need to identify the physical quantities and interpret the proposed relations and their conditions. The worked cases add their own preparation: elementary motion and energy calculations, a spatial continuity equation, and charge storage. These are different demonstrations of the same construction.

If a known physical account already supplies the required result, use it. If a balance alone settles the question, stop there. C.29.BB supplies that general balance method. Use PHY.5 when choosing which physical detail to retain; use this pattern when assembling the retained physical relations. Once that account is settled, MMP.10 and C.29.2 help formulate and obtain its mathematical consequences.