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Grade 11General Physics

A thin rod of length L is falling freely in horizontal position from a height H above the surfaceof the table. In such a way that the end of rod just hits the edge of the table. This collision is instaneous and elastiic. At what time after collision does the rod perform a whole revolution? H=80 cm L=40cm

Profile image of Abhigyan
11 Years agoGrade 11
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1 Answer

Profile image of Abhishek Kumar
11 Years ago
Apply conservation of angular momentum along the axis coinciding with the line of collission.
So,
m\sqrt{2gH}L/2 = I\omega (I = ml2/3 about the same axis)
Now, \omega is known.
so, use this equation :

489-579_79c4deda4cdc6a318b14f8b1743f2fc2.png
Initial value of theta is zero.
\theta = \pi/2 and \alpha = g/(L/2)
Put the values and get t.