The phenomenon of recoil is usually explained to students in the context of Newton's third law. Typically, when a projectile is fired, the recoil of the launch mechanism is interpreted as a reaction to the ejection of the smaller projectile. The same phenomenon is also interpreted in the context of the conservation of linear momentum, which is closely related to Newton's third law. Since the actual microscopic causes of recoil differ from one problem to another, some students (and teachers) may not be satisfied with understanding recoil through the principles of conservation of linear momentum and Newton's third law. For these students, the origin of the recoil motion should be presented in more depth.

We divided our high school physics teaching experience into three groups: first year teaching physics, second or third year teaching physics, and four or more years of experience teaching physics. We did this because everything is new for teachers teaching a course for the first time. The second and third time through the course, teachers learn from past experiences and hone their approaches. By the time a teacher is in the fourth year of teaching a course, he or she is more comfortable with the material and better able to understand the ways in which different approaches work with different topics.