There are many difficulties for students when it comes to learning the fundamental relationships in Newtonian mechanics, which is supported by manifold research. Even after class the understanding of Newton's laws of motion is often inadequate, which is problematic because classical mechanics is the foundation of many other areas in physics and the natural sciences in general. These problems stem from the fact that students' preconceptions in the field of mechanics are especially diverse and persistent because they are strengthened in everyday life over the course of many years. These preconceptions and the fact that idealized situations are often most prominent in class can lead to a felt incompatibility of everyday life and physics lessons. The computer can be a tool to reduce that gap by discussing complex and authentic motions in class without the need to use difficult mathematics, which can lead to reduction in certain unwanted preconceptions. Two different ways of using the computer in mechanics class, computational modeling and video motion analysis, are discussed in this article. The two methods are compared in a pre-post design study with N = 267 students from 11th grade from German high schools in regard to the overall conceptual understanding of Newton's first two laws. The results suggest that both methods can be successful in teaching the basic concepts of Newtonian dynamics and no differences can be seen in the overall scores for conceptual understanding. Furthermore, it seems that computational modeling performs better in items regarding Newton's first law due to a comparatively greater reduction of a specific preconception, which is further discussed in the article.