Light can be reflected by a mirror, refracted by a lens, or absorbed by the object. Good explanations are based on evidence from investigations. Energy is transferred in many ways. Changes might occur, for example, in properties of materials, position of objects, motion, and form and function of systems. Interactions within and among systems result in change.
Models help scientists and engineers understand how things work.
Models take many forms, including physical objects, plans, mental constructs, mathematical equations, and computer simulations. One way to describe something is to say how it is like something else. What kind of a model to use and how complex it should be depends on its purpose. The usefulness of a model may be limited if it is too simple or if it is needlessly complicated. Choosing a useful model is one of the instances in which intuition and creativity come into play in science, mathematics, and engineering.