PHY.4:4.2 - Construct the transformation of the situation

Describe what happens to every relevant participant and condition under the proposed change. If an apparatus is rotated, what happens to gravity, nearby surfaces, an applied field and its preparation? If two participants are exchanged, which material properties and connections move with them?

Separate two comparisons:

• Changed coordinates: the same physical situation is expressed with different components or labels. Transform every quantity representing that situation consistently.
• Changed physical situation: participants or conditions are changed. Explain which physical premise predicts corresponding behavior in the new situation.

For an isotropic material, all spatial directions are physically equivalent under the stated conditions. An oriented material can also be described in rotated coordinates; its material direction must then rotate in the description. These are different premises for restricting a response.

Select the actual transformation class. A justified rotation condition supplies rotation consequences. Reflection, time reversal, scaling or exchange requires its own physical grounds when used. PHY.1 supplies the detailed work for a scaling comparison.

A thought comparison can be enough. When a physical premise is unsettled, identify a rival case that could make the responses differ. C.11.DUA helps decide whether resolving that difference is worth the work needed now.