BM Sharma Solutions for Chapter: Newton's Laws of Motion II, Exercise 4: DPP

A force, $F=\left(t\right) \mathrm{N}$ is applied to a block $A$ as shown in figure, where $t$ is time in $\mathrm{second}$. The force is applied at$t=0$ when the system was at rest. Which of the following graph correctly gives the frictional force between $A$ and horizontal surface as a function of time $t$?

(Assume that at $t=0$, tension in the string connecting the two blocks is zero).

With reference to the figure shown, if the coefficient of friction at the surfaces is$0.42$, then the force required to pull out the $6.0 \mathrm{kg}$block with an acceleration of $1.50 \mathrm{m} {\mathrm{s}}^{-2}$ will be,

The coefficient of friction between $4 \mathrm{kg}$and $5 \mathrm{kg}$blocks is $0.2$and between $5 \mathrm{kg}$block and ground is$0.1$, respectively. Choose the correct statements.

A block $A$ with mass $100 \mathrm{kg}$ is resting on another block $B$ of mass $200 \mathrm{kg}.$ As shown in figure, a horizontal rope tied to a wall holds it. The coefficient of friction between $A$ and $B$ is $0.2$ while coefficient of friction between $B$ and the ground is $0.3.$The minimum required force $F$ to start moving $B$ will be

​​A body $B$ lies on a smooth horizontal table and another body $A$ is placed on $B$. The coefficient of friction between $A$ and $B$ is $\mu$. What acceleration given to $B$ will cause slipping to occur between $A$ and $B$?

A $40\mathrm{ }\mathrm{kg}$ slab rests on a frictionless floor and a $10 \mathrm{kg}$ block rests on the top of the slab. The static coefficient of friction between the block and slab is $0.60$ while the kinetic friction is $0.40$. The $10 \mathrm{kg}$ block is acted upon by a horizontal force $100 \mathrm{N}$. If $g=9.8 \mathrm{m} {\mathrm{s}}^{-2}$, the resulting acceleration of the slab will be,

In the figure, $m_{\mathrm{A}}=m_{\mathrm{B}}=m_{\mathrm{C}}=60 \mathrm{kg}$ The coefficient of friction between $C$ and ground is $0.5$, between $B$ and ground is $0.3$, between $A$ and $B$ is $0.4$ . $C$ is pulling the string with the maximum possible force without moving. Then, the tension in the string connected to $A$ will be

In the system shown in figure the friction coefficient between ground and bigger block is $\mu .$ There is no friction between the blocks. The string connecting both the blocks is light; all three pulleys are light and frictionless. Then the minimum limiting value of $\mu$so that the system remains in equilibrium is