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The ring which can slide along the rod a...

The ring which can slide along the rod are kept at mid point of a smooth rod of length L. The rod is rotated with constant angular velocity `omega` about vertical axis passing through its one end. The ring is released from mid point. The velocity of the ring, when it just leaves the rod is = `(sqrt(x))/(2)omegaL`. Then x is equal to

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To solve the problem step by step, we need to analyze the motion of the ring as it slides along the rod and determine its velocity when it leaves the rod. ### Step 1: Understand the System The ring is initially at the midpoint of a smooth rod of length \( L \). The rod is rotated about a vertical axis with a constant angular velocity \( \omega \). When the ring is released, it will experience a centrifugal force due to the rotation. ### Step 2: Identify the Forces The centrifugal force acting on the ring when it is at a distance \( x \) from the axis of rotation is given by: \[ F_c = m \omega^2 x \] where \( m \) is the mass of the ring. ### Step 3: Relate Centrifugal Force to Acceleration The centrifugal force can be equated to the mass times the acceleration experienced by the ring: \[ m \omega^2 x = m \frac{dv}{dt} \] Since the ring is sliding, we can express the acceleration in terms of the change in velocity with respect to the position \( x \): \[ \omega^2 x = v \frac{dv}{dx} \] ### Step 4: Integrate Both Sides To find the relationship between velocity and position, we need to integrate both sides. Rearranging gives: \[ v dv = \omega^2 x dx \] Integrating from \( x = L/2 \) to \( x = L \) and from \( v = 0 \) to \( v \): \[ \int_0^v v \, dv = \int_{L/2}^{L} \omega^2 x \, dx \] This results in: \[ \frac{v^2}{2} = \omega^2 \left[ \frac{x^2}{2} \right]_{L/2}^{L} \] ### Step 5: Calculate the Integral Calculating the definite integral: \[ \frac{v^2}{2} = \omega^2 \left( \frac{L^2}{2} - \frac{(L/2)^2}{2} \right) \] \[ = \omega^2 \left( \frac{L^2}{2} - \frac{L^2/4}{2} \right) = \omega^2 \left( \frac{L^2}{2} - \frac{L^2}{8} \right) \] \[ = \omega^2 \left( \frac{4L^2}{8} - \frac{L^2}{8} \right) = \omega^2 \left( \frac{3L^2}{8} \right) \] ### Step 6: Solve for \( v \) Thus, we have: \[ \frac{v^2}{2} = \frac{3\omega^2 L^2}{8} \] Multiplying both sides by 2 gives: \[ v^2 = \frac{3\omega^2 L^2}{4} \] Taking the square root: \[ v = \sqrt{\frac{3}{4}} \omega L = \frac{\sqrt{3}}{2} \omega L \] ### Step 7: Final Comparison The problem states that the velocity of the ring when it just leaves the rod is given by: \[ v = \sqrt{\frac{x}{2}} \omega L \] Comparing both expressions for \( v \): \[ \frac{\sqrt{3}}{2} \omega L = \sqrt{\frac{x}{2}} \omega L \] Dividing both sides by \( \omega L \) (assuming \( \omega L \neq 0 \)): \[ \frac{\sqrt{3}}{2} = \sqrt{\frac{x}{2}} \] Squaring both sides: \[ \frac{3}{4} = \frac{x}{2} \] Multiplying both sides by 2: \[ x = \frac{3}{2} \cdot 2 = 3 \] ### Conclusion Thus, the value of \( x \) is: \[ \boxed{3} \]
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