Problem statementSolution video |

**DISCUSSION THREAD**

**Discussion and hints:**

Recall the following *f**our-step plan* outline in the lecture book and discussed in lecture:

**Step 1: FBDs**

Draw a *single* free body diagram for the system made up of the disk, bar and block, *combined*.

**Step 2: Kinetics (work/energy)**

- Write down the kinetic expressions for the three bodies in the system, individually, and then add those together to find the total KE for the system of your FBD.
- Do the same for the potential energies: write down the PEs for each body individually and add together.
- Also, based on your FBD above, which, if any force or couple, does nonconservative work on the system in your FBD? Determine work for such a force/couple.

**Step 3: Kinematics**

Since the bar is welded to the disk, the angular velocities of the bar and disk are the same. The no-slip condition at the point of contact of the disk and block enforces a constraint between the rotation rate of the disk and the translational speed of the block. What is that constraint?

**Step 4: Solve**

Solve your equations above for the angular velocity of the disk.

Any questions?