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Physics · SYSTEMS OF PARTICLES AND ROTATIONAL MOTION
हिन्दीA ladder of length \( 3\text{ m} \) and mass \( 20\text{ kg} \) leans against a smooth frictionless vertical wall with its foot placed \( 1\text{ m} \) from the wall. Assuming the center of gravity is at its midpoint, the normal reaction force exerted by the vertical wall on the ladder is: (Take \( g = 9.8\text{ m/s}^2 \))
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Correct answer · Option A
\( 34.6\text{ N} \)
Explanation
Vertical height \( h = \sqrt{3^2 - 1^2} = \sqrt{8} = 2\sqrt{2}\text{ m} \). Taking torque about the base point \( A \): \( F_1(2\sqrt{2}) - W(0.5) = 0 \implies F_1 = \frac{W}{4\sqrt{2}} = \frac{196}{4\sqrt{2}} \approx 34.6\text{ N} \).
