Three identical blocks of masses $\mathrm{m} = 2 \mathrm{~kg}$ are drawn by a force $\mathrm{F} = 10.2 \mathrm{~N}$ with an acceleration of $0.6 \mathrm{~ms}^{-2}$ on a frictionless surface, then what is the tension (in N) in the string between the blocks $B$ and $C$?
(1) 9.2
(2) 7.8
(3) 4
(4) 9.8

A block of mass $M$ is pulled along a horizontal frictionless surface by a rope of mass m. If a force P is applied at the free end of the rope, the force exerted by the rope on the block is
(1) $\frac{\mathrm{Pm}}{\mathrm{M} + \mathrm{m}}$
(2) $\frac{\mathrm{Pm}}{\mathrm{M} - \mathrm{m}}$
(3) $P$
(4) $\frac{\mathrm{PM}}{\mathrm{M} + \mathrm{m}}$

Two blocks of mass $M_1 = 20\mathrm{~kg}$ and $M_2 = 12\mathrm{~kg}$ are connected by a metal rod of mass 8 kg. The system is pulled vertically up by applying a force of 480 N as shown. The tension at the mid-point of the rod is:
(1) 144 N
(2) 96 N
(3) 240 N
(4) 192 N

Three blocks $M_1, M_2, M_3$ having masses $4\mathrm{~kg}, 6\mathrm{~kg}$ and $10\mathrm{~kg}$ respectively are hanging from a smooth pulley using rope 1, 2 and 3 as shown in figure. The tension in the rope 1, $T_1$ when they are moving upward with acceleration of $2\mathrm{~ms}^{-2}$ is $\_\_\_\_$ $\mathrm{N}$ (if $\mathrm{g} = 10\mathrm{~m/s}^2$).