posted by Ryan on .
In the figure below, two particles, each with mass m = 0.82 kg, are fastened to each other, and to a rotation axis at O, by two thin rods, each with length d = 10 cm and mass M = 2.0 kg. The combination rotates around the rotation axis with angular speed ù = 0.34 rad/s.
(a) Measured about O, what is the combination's rotational inertia?
(b) What is the combination's kinetic energy?
The figure looks like this:
At first I used (1/3)(M)(L^2) to find the moment of inertia but that is not working. I also tried finding the individual kinetic energies and the total kinetic energy (I converted omega to velocity using radius of .2m)but neither worked. I've tried some other methods but just cant seem to get the right answer.