Two blocks of masses $5\, kg$ and $4\, kg$ are in contact with each other on a frictionless table. When a horizontal force of $9\, N$ is applied to the block of mass $5\, kg$,then the value of the force of contact between the two blocks is ........ $N$.

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

Two blocks $A$ and $B$ of mass $m$ and $2m$ respectively are connected by a massless spring of force constant $k$. They are placed on a smooth horizontal plane. The spring is stretched by an amount $x$ and then released. The relative velocity of the blocks when the spring comes to its natural length is:

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 ............ $N$.

For the given figure,find the value of $m$ (in $kg$) for which the blocks have an acceleration of $\frac{8}{13}g$. The block on the incline has a mass of $100 \, g = 0.1 \, kg$ and the hanging block on the left has a mass of $50 \, g = 0.05 \, kg$. The surface is frictionless $(\mu = 0)$.

$A$ mass of $10 \, g$ is suspended by a string and the entire system is falling with a uniform acceleration of $400 \, cm/s^2$. The tension in the string will be.......... $dyne$ $(g = 980 \, cm/s^2)$.