A system of men and trolley is shown in figure. To the left end of the string, a trolley of mass...

A system of men and trolley is
shown in figure. To the left end
of the string, a trolley of mass \( M \)
is connected on which a man of
mass \( m \) is standing. To the right
end of the string another trolley
of mass \( m \) is connected on which
a man of mass \( M \) is standing. Initially, the system is at rest. All
of a sudden both the men leap upwards simultaneously with the same velocity \( u \) w.r.t. ground.
Find the relative velocity of left man with respect to his trolley just after he leaps upwards.
(1) \( \frac{m u}{m+M} \)
(2) \( \frac{M u}{m+M} \)
(3) \( \frac{2 m u}{m+M} \)
(4) \( \frac{2 M u}{m+M} \)