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Question: Answered & Verified by Expert
A uniform rod of length \( L \) is hinged at one end and initially held in horizontal position. After it is released, find its angular
speed when the rod becomes vertical.
PhysicsRotational MotionJEE Main
Options:
  • A \( (g L)^{1 / 2} \)
  • B \( \left(\frac{2 g}{L}\right)^{1 / 2} \)
  • C \( \left(\frac{3 g}{L}\right)^{1 / 2} \)
  • D \( \left(\frac{4 g}{L}\right)^{1 / 2} \)
Solution:
2645 Upvotes Verified Answer
The correct answer is: \( \left(\frac{3 g}{L}\right)^{1 / 2} \)

The gain in kinetic energy, KE=12ml23ω2

Loss in potential energy, -U=mghloss, where hloss=L2 is the loss of height of the center of mass.

 

By conservation of mechanical energy, KE=-U

mgL2=12mL23ω2ω=3gL12

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