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## 6 thoughts on “Homework H.2.E”

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Hi,

So I'm trying to figure out how to start this problem. I'm thinking fo relating the velocity of point O to the velocity at A with the goal of finding omega for O. But, because A is so far away from O and we don't know its position relative to O, what vector do we use?

What you want to do is solve for the velocity of B from the perspective of A and O separately like we did in class today. To get the velocity of O you have to do it in relation to point C which is not moving as the disc is rolling without slipping. In the end you should get 2 Velocity of B equal to 2 vectors which gives you a pretty simple system of equations. The exact same method applies for part B with the accelerations!

I moved my point A down so it was on the wheel because the velocity would still be the same there. Then I related point N to A and solved for the velocity of N. Since N is the velocity of the inner wheel you can see that v_D is the same but in the positive direction and v_Q is in the negative direction (because there is no slipping). I'm not 100% sure if this is correct, but I think the idea is to relate the outer wheel to the inner wheel in some capacity.

@Paul V Richards

I believe that the angular velocity is equal across the problem but I am not certain.

OK, so if I use C as my instant center, and find omega C, when solving for Q I need to take something extra into account? I believe that N will travel the same speed at D, but H will not with Q. Q will move up with H according to omega C cross CH but also minus the speed of N (or D)? not sure if I have the right thinking down here.