Three blocks of masses $3\, kg, 2\, kg$ and $1\, kg$ are placed side by side on a smooth  surface as shown in figure. A horizontal force of $12\,N$ is applied to $3\, kg$ block. The  net force on $2\, kg$ block is ............ $N$

Three blocks are connected as shown in figure on a horizontal frictionless table. If $m_1 =  1kg, m_2 = 8kg, m_3 = 27\, kg$ and $T_3 = 36N, T_2$ will be ............ $N$

Three blocks $A, B$ and $C$ of masses $4\, kg$, $2\, kg$ and $1\, kg$ respectively, are in contact on a frictionless surface, as shown. If a force of $14\, N$ is applied on the $4\, kg$ block, then the contact force between $A$ and $B$ is .......... $N$

$Assertion$ : A man and a block rest on smooth horizontal surface. The man holds a rope which is connected to block. The man cannot move on the horizontal surface

$Reason$ : A man standing at rest on smooth horizontal surface cannot start walking due to absence of friction (The man is only in contact with floor as shown).

A block '$A$' takes $2\,s$ to slide down a frictionless incline of $30^{\circ}$ and length ' $l$ ', kept inside a lift going up with uniform velocity ' $v$ '. If the incline is changed to $45^{\circ}$, the time taken by the block, to slide down the incline, will be approximately $........\,s$

Figure shows a uniform rod of length $30 \,cm$ having a mass $3.0 \,kg$. The rod is pulled by constant forces of $20 \,N$ and $32 \,N$ as shown. Find the force exerted by $20 \,cm$ part of the rod on the $10 \,cm$ part (all surfaces are smooth) is ......... $N$