THE CONCEPT OF RELATIVE MOTION FROM A SIMPLE EXPERIMENTAL APPROACH
One of the most important concepts in classical mechanics is the concept of the observer. The analysis of the motion of a body in a non-inertial frame from the point of view of inertial and non-inertial observers, involves the appearance of fictitious forces, also called pseudo-forces. In the classical example of a rotating reference frame, three fictitious forces can be considered, namely, the Coriolis force, the centrifugal force, and the Euler force However, the weakness of these forces compared to most typical forces which appears in everyday life, make them, in general, a difficult concept to be understood by physics students.
In order to understand pseudo-forces in a rotating reference frame, we introduce in this work a simple experimental setup which can be used to visualize these forces. The utilization of this setup in classroom demonstrations allows clarifying the importance of the observer in the classical mechanics.