General results

In general our findings are in agreement with former studies [2] [3]. The majority of our students (about 90%) do not succeed to overcome their daily life concepts about motion and driving force and are not able to apply their knowledge about Newtons 2nd law to a real situation.

Most students are not able to give a satisfying explanation for the fact that all objects are accelerated in free fall by the same amount, independent of their mass. Knowledge about the difference between inertial mass and gravitational mass can hardly be detected and most students do not know how and when to apply the principle of superposition