Physics LAB

The moment of inertia is a measure of an object’s resistance to changes in its rotation. It must be very specific to the chosen axis of rotation. Also, it is specific to the mass and shape of the object, including the way that is mass is distributed in the object. Moment of inertia is usually quantified in kgm2. An object’s where the mass is concentrated very close to the center of axis of rotation will be easier to spin than an object of identical mass with the mass concentrated far from the axis of rotation. A common example is to think of an ice skater who is spinning. As the skater begins a spin, she will put her arms out away from her body to create a slow spin. As she tucks her arms in, she will spin much more rapidly. By moving her mass closer to the axis, she reduced her moment of inertia.
Many practical applications for this experiment exist. Car manufacturers study it carefully to determine how quickly a car will spin out of control. Here, a higher moment is created such that the car is less likely to lose control in a spin. Many sports also use the concept, as in the example of the skater. Divers use this so they can use the lowest moment of inertia and fastest spin to move seamlessly and enter the water. The same goes for baseball players and golfers so that they can move have a very effective swing and hit the ball at the correct angles.
Going down to the basics, the moment of inertia of an object can be found by breaking the object into little bits and multiplying the mass of each piece by its distance from the rotational axis squared. Adding all of these up, the moment of inertia can be defined as the quantity
I= , where M= mass and R= radius of the object.
Fortunately for us, for the most common objects rotating about typical axes of rotation, the summations have already been calculated. For this experiment, we used these pre-calculated formulas and values for moment of inertia for theoretical purposes. For objects where the mass is