Two blocks of masses $6 \ kg$ and $4 \ kg$ are placed in contact with each other on a smooth surface as shown. If a force of $5 \ N$ is applied on the heavier block,the force on the lighter block is (in $N$)

Two masses $A$ and $B$,each of mass $M$,are connected by a massless spring. $A$ force $F$ acts on the mass $B$ as shown in the figure. If the mass $A$ starts moving away from mass $B$ with acceleration $a$,then the acceleration of mass $B$ will be:

Two blocks of mass $M_1 = 20\,kg$ and $M_2 = 12\,kg$ 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 ........ $N$.

$A$ monkey of mass $20\,kg$ is holding a vertical rope. The rope will not break when a mass of $25\,kg$ is suspended from it but will break if the mass exceeds $25\,kg$. What is the maximum acceleration with which the monkey can climb up along the rope in $m/s^2$? (Take $g = 10\,m/s^2$)

$A$ monkey of mass $m$ is climbing a rope hanging from the roof with acceleration $a$. The coefficient of static friction between the body of the monkey and the rope is $\mu$. Find the direction and value of the friction force on the monkey.

$A$ block of mass $m_1$ rests on a horizontal table. $A$ string tied to the block is passed over a frictionless pulley fixed at the end of the table,and to the other end of the string is hung another block of mass $m_2$. The acceleration of the system is