MCQ
On $a$ smooth horizontal plane, $a$ uniform string of mass $M$ and length is lying in the state of rest. $A$ man of the same mass $M$ is standing next to one end of the string. Now, the man starts collecting the string. Finally the man collects all the string and puts it in his pocket. What is the displacement of the man with respect to earth in the process of collection?
  • A
    $L / 2$
  • $L / 4$
  • C
    $L / 8$
  • D
    none 

Answer

Correct option: B.
$L / 4$
b
$M \frac{L}{2}=2 M \Delta x$

$\left[\Delta x=\frac{L}{4}\right]$

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