Obtaining moments of inertia using rotation sensor and filming with cellphone

The moment of inertia of a thin rectangular rod and a hollow cylinder was determined using different methods. The first method used the dimensions of the objects to insert them into theoretical equations and thus calculate the moments of inertia. The second method used the laws of rotation and translation dynamics together with energy concepts to obtain equations involving measurable physical parameters, allowing the moment of inertia to be calculated indirectly. In this case, three different experiments were carried out. The first experiment used a rotation sensor and the others used filming with a mobile phone. All indirect measurements resulted in very close values and with percentage differences ≈ 10% relative to the value calculated from the dimensions of the objects.

Keywords
Moment of inertia; rotation dynamics; physics teaching; instrumentation