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dttah
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Homework Statement
A system is made of the following things:
A homogeneous disk of mass m = 4kg.
Having radius r = 80cm's.
A point P (m = 2kg) free to rotate around a horizontal axis which is perpendicular to the disk in point A.
AO = OP/2
If the system starts from rest and AP forms a 90° angle with the vertical axis, find the angular velocity and the action on the axis (not sure what this means) in point A, when the system is passing through its equilibrium position.
Homework Equations
The Attempt at a Solution
******Completely not sure about the following:
I am just starting out with rigid bodies, so I will be a lil' slow. As long as I understood I should find the center of mass, so uhm.
The disk is homogenous so the center of mass would be the center.
Let O be the origin of our system.
The center of mass would be:
[itex]\frac{0*4+0.8*2}{6}[/itex]
So the center of mass would be (0,26,0);
Uhm, now I thought I would have found the radius of the circumference having center A and radius Ax (center of mass).
So I did:
r = OP/2 + 0.26 = 0.66.
And now I am completely stuck.
Could you please give away some hints, and check if I did correctly 'till now or I completely missed it? Thanks.
The picture is this one, forget about the italian, it'd be the circumference on the bottom:
http://www.quellidiinformatica.org/upload/8/0/img007.jpg