Exploring the Concept of Rotation - Lab Report Example

The dynamic and static moment of inertia was different for both experiments. The torque applied produced the same energy for both the longest and shortest axis rotation. On the shortest axis, the dynamic moment of inertia was more than the static inertia. This also applies to the longest axis where the dynamic moment is far larger than the static.

Discussion
The difference noticed from the determined dynamic and static moment of inertias is an illustration that the rotational axis has a core function in rotational motion. In normal cases, especially where there are no deformations, the dynamic moment of inertia and static moment of inertia are equal, except for small errors that may result from experimental undertakings. The difference exhibited between the two moments of inertia can be attributed to the change in the rotational axis. As the axis is moved from the shortest hole to the longest hole, the deformation (change) contributes to the change in the resistance of the object to angular acceleration. Just like in linear motion where, when the object is rotated about a long axis, the acceleration is likely to reduce as compared to when subjected to a shorter axis.
Further, friction was also determined to be a contributing factor to the difference between the static and dynamic moment of inertia. Intuitively, dynamic cases are susceptible to friction effect because of the movement exhibited, unlike in static where an object is fixed. As shown by the higher value of the dynamic moment of inertia than a static moment of inertia, friction had a stake in this. In which case, friction resulted in a too high value for Id during the experiment. Friction force acts in slowing down the rotational acceleration consequently enforcing the ability of the object to resist the angular acceleration. Consequently, the addition of friction adds to the resistance of the object to friction, which in turn increases the total dynamic moment of inertia. In the case of a static moment of inertia, there is no friction exhibited consequently the resistance (moment of inertia) is not in any way affected.
The results show that the rotational kinetic energy is equal to the work contributed by the applied torque. This can be explained by the fact that the rotational work is τθ and the angular acceleration α through Newton’s second law is determined by dividing the final velocity by time. In which case, the average velocity resulting therein is half of the final velocity. Consequently, this insinuates that the applied rotational kinetic energy is the same as the work done by the torque (Myers 35).
Even though the experiment was successful in meeting its objective, possible sources of error may have contributed to the slight uncertainties witnessed. For instance, while taking the experimental data, there were mistakes occurring when adjusting the equipment to fit the required measurements. Readings taken may have been slightly altered by this. Read More