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¢ô (20 points) The collar A of mass m slides on the weightless rod OB, which rotates with a constant

???. A pin attached to the collar engages the fixed vertical slot. Neglecting angular velocity ?friction, determine (a) the absolute acceleration of the collar A; (b) the force exerted on the pin by the slot; (c) the force exerted on the collar by the rod. Express you answers in terms of ?, ?, m, b, and g.

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Fig. IV

¢õ (20 points) Fig. V shows a homogeneous slender bar AB of mass m and length L. When the bar was in

the position ?=0, it was displaced slightly and released from rest. Neglect friction and assume that end A does not lose contact with the vertical surface.

(1) Determine the angular velocity and angular acceleration of the bar as functions of the angle ? using the theorem of the kinetic energy;

(2) Find the reactions at A and B as functions of the angle ? using the differential equations of plane motion of rigid body.

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Fig. V