Hmwk 8: Torque and Angular Acceleration

To find the acceleration a of a particle of mass m, we use Newton's second law: Fnet=manet=, where Fnetnet is the net force acting on the particle.To find the angular acceleration of a rigid object rotating about a fixed axis, we can use a similar formula: net=Inet=, where net=net= is the net torque acting on the object and I is its moment of inertia.

Assume that the mass of the swing bar, as shown in the figure, is negligible.(Figure 1) Find the magnitude of the angular acceleration of the seesaw.Express your answer in terms of some or all of the quantities m11, m22, l, as well as the acceleration due to gravity g.

Now consider a similar situation, except that now the swing bar itself has mass mbarbar.(Figure 2) Find the magnitude of the angular acceleration of the seesaw.Express your answer in terms of some or all of the quantities m11, m22, mbarbar, l, as well as the acceleration due to gravity g.