Each law has the same format
when written using this approach, so students begin to see similar
terms and physical concepts.
When solving problems, students are encouraged
to write the pertinent basic law and then develop a problemspecific
model. Thus, students repeatedly see connections back to the basic
laws by developing a model instead of memorizing special cases.
For example, consider how the linear momentum
equation could be applied to different problems:
 For a projectile (a closed system), the
terms drop out, and Newton's second law is recovered as,
 For a closed system of two cars colliding
at an intersection with negligible friction forces, and the terms
drop out; thus,
 For a fluid flowing steadily through
a pipe elbow (an open system); thus, the surface forces, the system
weight, and the mass transport of momentum are related by the
equation.
