Q. In the given arrangement, $n$ number of equal masses are connected by strings of negligible masses. The tension in the string connected to $n$th mass is
A) $\frac{mMg}{nm + M}$
B) $\frac{mMg}{nmM}$
C) $mg$
D) $mng$
Explanation
(a) The system may be represented as follow
[image:5_image182.emf]
From the force diagram,
$Mg - T = Ma$ …(i)
and $T = nma$ …(ii)
From Eqs. (i) and (ii),
$a = \frac{Mg}{nm + M}$
The fore diagram of $n$th block is shown in figure
[image:5_image182.emf]
From the figure,
$T_{n} = ma = \frac{mMg}{nm + M}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.