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 *individual* free body diagrams for the bar and the disk.

* Step 2: Kinetics (Newton/Euler)*Write down the Newton/Euler equations for the disk and for the bar based on your FBDs above.

**Step 3: Kinematics**

You need to use the rigid body acceleration equations to relate the accelerations of O and the center of mass of the bar, G, through the angular acceleration of the bar. Also, you need to relate the acceleration of O to the angular acceleration of the disk.

**Step 4: Solve**

Solve your equations for the angular accelerations of the bar and the disk.

Any questions?

Does the internal force at O act in the direct of the bar or are they independent?

I think it may just be based on the way you draw them in the FBD.

No because the bar has its own weight, so it is not a two force member

Do we not need to know the coefficient of kinetic friction?

nevermind

How many equations do we need to solve this problem? Do we need to relate acceleration of O to the contact point with the ground?