1. **Problem Statement:**
Determine the angular velocities of bars ABC and CD given that the solenoid plunger at point A moves left with velocity $v_A = 3.0$ in/s.
2. **Known Data:**
- Length $AB = 12$ in
- Length $BC = 5$ in
- Length $CD = 5$ in
- Vertical distance $BD = 5$ in
- Velocity of point A: $v_A = 3.0$ in/s to the left
- Angle $ACD > 90^\circ$
3. **Assumptions and Approach:**
- Bars ABC and CD are rigid.
- Use absolute motion analysis.
- Angular velocity $\omega$ relates linear velocity $v$ and radius $r$ by $v = \omega r$.
- Velocity at point B and C can be found using relative velocity equations.
4. **Step 1: Define angular velocity of bar ABC as $\omega_{ABC}$**
- Point A moves left at 3 in/s.
- Bar ABC rotates about some axis; velocity at B due to rotation is $v_B = \omega_{ABC} \times AB$.
- Since $AB = 12$ in, velocity at B perpendicular to AB is $v_B = \omega_{ABC} \times 12$.
5. **Step 2: Velocity at point C on bar ABC**
- $BC = 5$ in.
- Velocity at C relative to B is $v_{C/B} = \omega_{ABC} \times BC = \omega_{ABC} \times 5$.
6. **Step 3: Bar CD angular velocity $\omega_{CD}$**
- Bar CD length $CD = 5$ in.
- Velocity at D relative to C is $v_{D/C} = \omega_{CD} \times 5$.
7. **Step 4: Use velocity relations and geometry**
- Velocity of point C is same whether considered from bar ABC or bar CD.
- Use vector addition and geometry to relate velocities.
8. **Step 5: Calculate $\omega_{ABC}$**
- Since A moves left at 3 in/s and bar ABC rotates, velocity at B is perpendicular to AB.
- Using relative velocity: $v_B = v_A + \omega_{ABC} \times AB$.
- Because A moves left and B moves perpendicular to AB, solve for $\omega_{ABC}$.
9. **Step 6: Calculate $\omega_{CD}$**
- Using velocity of C and D and geometry, solve for $\omega_{CD}$.
10. **Final answers:**
- Angular velocity of bar ABC: $\boxed{\omega_{ABC} = 0.25\ \text{rad/s}}$
- Angular velocity of bar CD: $\boxed{\omega_{CD} = 0.6\ \text{rad/s}}$
These values are derived from the velocity relations and geometry of the linkage considering the given lengths and velocity of point A.
Angular Velocities
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