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Physics · WORK, ENERGY AND POWER
हिन्दीA bob of mass \( m \) is suspended by a light string of length \( L \). What minimum horizontal velocity \( v_0 \) must be imparted to the bob at its lowest point so that it completes a full vertical circular loop?
Correct answer · Option 2
\( \sqrt{5gL} \)
Explanation
At the topmost point C, the condition for completing the circle is \( T_C \ge 0 \implies v_C = \sqrt{gL} \). By conservation of mechanical energy, \( \frac{1}{2}mv_0^2 = \frac{1}{2}m v_C^2 + 2mgL \), which yields \( v_0 = \sqrt{5gL} \).
