Moments of inertia
Spheres
Slabs
Thin rods
10.5 - Sample problem: a seesaw
The axis of rotation is the point where the fulcrum touches the midpoint of the plank. The plank itself creates no net torque since it is balanced
at its middle. For every particle at a given distance from the axis that creates a clockwise torque, there is a matching particle at the same
distance creating a counterclockwise torque. However, the plank does factor into the moment of inertia.The seesaw plank is horizontal. Its
mass is 36.5 kg, and it is 4.40 m long.
What is the initial angular acceleration
of this system?
(^192) Copyright 2007 Kinetic Books Co. Chapter 10