Two masses of $5 \,kg$ and $3 \,kg$ are suspended with the help of massless inextensible strings as shown in the figure below. When the whole system is moving upwards with an acceleration of $2 \,m/s^2$, the value of $T_1$ is (use $g = 9.8 \,m/s^2$): (in $\,N$)

$A$ monkey of mass $40 \, kg$ climbs on a rope which can stand a maximum tension of $600 \, N$. In which of the following cases will the rope break: the monkey
$(a)$ climbs up with an acceleration of $6 \, m \, s^{-2}$
$(b)$ climbs down with an acceleration of $4 \, m \, s^{-2}$
$(c)$ climbs up with a uniform speed of $5 \, m \, s^{-1}$
$(d)$ falls down the rope nearly freely under gravity? (Ignore the mass of the rope).

Two blocks,each of mass $M$,are initially at rest on frictionless surfaces as shown in the figure. If the pulleys are light and frictionless,and the block of mass $M$ on the incline is allowed to move down,then the tension in the string will be$-$

On a smooth plane surface,two blocks $A$ and $B$ are accelerated by applying a force of $15 \, N$ on block $A$. If the mass of block $B$ is twice that of block $A$,the force on block $B$ is ........... $N$.

An elevator weighing $6000\,kg$ is pulled upward by a cable with an acceleration of $5\,ms^{-2}$. Taking $g$ to be $10\,ms^{-2}$,the tension in the cable is ............ $N$.

$A$ constant horizontal force $\overrightarrow{F}$ of magnitude $10 \,N$ is applied to a block $A$ and this produces an acceleration of magnitude $20 \,m/s^2$. If this block $A$ is then kept against another block $B$ of mass $1.5 \,kg$ as shown in the figure and a force $F^{\prime}$ of $20 \,N$ is applied, find the force on the block $B$. Neglect friction. (in $N$)