Filename: Rotational Inertia Variable

Mechanics

Name: Variable Rotational Inertia

Location:  L314

Equipment:  Rod with two sliding masses.

Presentation 1: Slide the masses along the rod to change the moment of inertia.  Students can feel the change with the resistance to rotation depending on where the mass is located.  If you slide and secure both masses to one end of the rod, it will be easier to balance on your hand or finger if the masses are at the highest point because the moment of inertia is higher.  BE CAREFUL!! Hazard if the masses slide.  Be sure the screws on the sliding rods are tight so the rods cannot slide!

Equipment:  Two Meter sticks, Modeling Clay, Rod Stand, Rod taped to table for a pivot point.

Presentation 2:  Place balls of clay on the ends of the meter sticks.  Stand them up so one has the clay ball at the top and the other has the clay at the bottom.  Release the meters sticks and the one with the clay ball at the top will fall slower due to the higher moment of inertia