$A$ system containing masses and pulleys connected on an inclined plane is shown in the figure. If the system is in equilibrium, then the value of $m$ is (in $\,kg$)

An elevator accelerates upwards at a constant rate. $A$ uniform string of length $L$ and mass $m$ supports a small block of mass $M$ that hangs from the ceiling of the elevator. The tension at distance $l$ from the ceiling is $T$. The acceleration of the elevator is

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

$A$ small block of mass $m$ is placed on a wedge of mass $M$ as shown,which is initially at rest. All the surfaces are frictionless. The spring attached to the other end of the wedge has a force constant $k$. If $a'$ is the acceleration of $m$ relative to the wedge as it starts coming down and $A$ is the acceleration acquired by the wedge as the block starts coming down,then the maximum retardation of $M$ is:

Consider two masses $m_1$ and $m_2$ connected through a pulley as shown in the figure. Mass $m_2$ starts from rest at height $h$ and falls down. With what speed does it hit the ground? (Assume no friction and massless strings and pulleys.)

$A$ block of mass $4 \,kg$ is suspended through two light spring balances $A$ and $B$ as shown in the figure. Then $A$ and $B$ will read respectively: