A pulse is generated at lower end of a hanging rope of uniform density and length $L$. The speed of the pulse when it reaches the mid point of rope is ......
A$\sqrt{2 g L}$
B$\sqrt{g L}$
C$\sqrt{\frac{g L}{2}}$
D$\frac{\sqrt{g L}}{2}$
Medium
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C$\sqrt{\frac{g L}{2}}$
c (c)
$v=\sqrt{\frac{T}{\mu}}$
Weight of the string below the rope stretching it $=\frac{\mu L}{2} g$.
This is equal to $T$ at the middle.
$\therefore \text { Velocity at middle }=\sqrt{\frac{\mu L g}{2 \mu}}$
$=\sqrt{\frac{g L}{2}}$
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