Three masses $M =100\,kg , m _{1}=10\,kg$ and $m_{2}=20\,kg$ are arranged in a system as shown in figure. All the surfaces are frictionless and strings are inextensible and weightless. The pulleys are also weightless and frictionless. $A$ force $F$ is applied on the system so that the mass $m_{2}$ moves upward with an acceleration of $2\,ms ^{-2}$. The value of $F$ is $......N$
$\left(\right.$ Take $\left.g =10\,ms ^{-2}\right)$
$3360$
$3380$
$3120$
$3240$
For the given figure what will be the contact force applied by $6\ kg$ block on $4\ kg$ block ............ $N$
A block of mass $m_1=1 \ kg$ another mass $m_2=2 \ kg$, are placed together (see figure) on an inclined plane with angle of inclination $\theta$. Various values of $\theta$ are given in List $I$. The coefficient of friction between the block $m _1$ and the plane is always zero. The coefficient of static and dynamic friction between the block $m _2$ and the plane are equal to $\mu=0.3$. In List $II$ expression for the friction on block $m _2$ given. Match the correct expression of the friction in List $II$ with the angles given in List $I$, and choose the correct option. The acceleration due to gravity is denoted by $g$.
[Useful information : $\tan \left(5.5^{\circ}\right) \approx 0.1 ; \tan \left(11.5^{\circ}\right) \approx 0.2 ; \tan \left(16.5^{\circ} \approx 0.3\right)$ ]
List $I$ | List $II$ |
$P.\quad$ $\theta=5^{\circ}$ | $1.\quad$ $m _2 g \sin \theta$ |
$Q.\quad$ $\theta=10^{\circ}$ | $2.\quad$ $\left(m_1+m_2\right) g \sin \theta$ |
$R.\quad$ $\theta=15^{\circ}$ | $3.\quad$ $\mu m _2 g \cos \theta$ |
$S.\quad$ $\theta=20^{\circ}$ | $4.\quad$ $\mu\left(m_1+m_2\right) g \cos \theta$ |
A block $B$ is placed on block $A$. The mass of block $B$ is less than the mass of block $A$. Friction exists between the blocks, whereas the ground on which the block $A$ is placed is taken to be smooth. $A$ horizontal force $F$, increasing linearly with time begins to act on $B$. The acceleration ${a_A}$ and ${a_B}$ of blocks $A$ and $B$ respectively are plotted against $t$. The correctly plotted graph is
$T_1$ and $T_2$ in the given figure are
Two block of masses $7\, kg$ and $5\, kg$ are placed in contact with each other on a smooth surface. If a force of $6\, N$ is applied on the heavier mass, the force on the lighter mass is ............ $N$