Rotational Dynamics essays

Rotational Dynamics essays In this experiment, the rotational motion of a solid pulley was studied. A mass was hung on a string, which was wrapped around the pulley. Using the mass hung on the string and accelerations given by a motion detector below the mass, the moment of inertia of the pulley can be discovered. This experiment showed that the average value for moment of inertia of the specific pulley was 0.00268 Kgm2 with an uncertainty of 0.00048 Kgm2. This same calculation was performed using the textbook definition for the moment of inertia of a solid disk. The given equation I=1/2MR2 , values for M and R were given and the resulting calculation produced a value for I of 0.00272 Kgm2 with uncertainty of 0.00015 Kgm2. The experiment showed that the values from both techniques of derivation come out to be the same value when the uncertainty is accounted for. In this experiment, the moment of inertia of a solid disk was studied. In particular, the forces needed to bring about a change in the rotational motion. For an extended object, a force acting anywhere away from the center of gravity will cause a rotation. This can be seen in the experiment because the force put on the pulley by the string is at a measurable distance from the center of gravity of the pulley. Torque is the name given to a force, which will change the rotation state of an object. The magnitude of the force times the distance the force is acting from the rotating axis. In this lab, the distance will always be the radius of the pulley. Only the tangential component of the force will cause a change in the rotational status of the object. The magnitude of the resulting torque is given by i = RFsin(f) where f is the angle between the radius F and the force F. The dynamic description for changes in angular velocity w: i = Ia = I*Dw/Dt is in the same form as that for changes in translational motion, from which it was derived (S&F). The moment of inertia of the pulley is gi...