A small block of mass $m$ is placed at one end of a plank of mass $M$ and length $l.$ A force $F$ is applied at the other end as shown in figure. If there is no friction at any contact surfaces, then

In the figure, the pulley $P$ moves to the right with a constant speed $u$. The downward speed of $A$ is $v_{\mathrm{A}}$ and the speed of $B$ to the right is $v_{\mathrm{B}}$.

Pulleys and threads shown in the figure are ideal

A block of mass $m$ slides down a rough inclined plane with an acceleration $\frac{g}{2}$

At $t=0,$ a small body is projected with a velocity of $30 \mathrm{m} {\mathrm{s}}^{–1},$ on a rough horizontal surface. The coefficient of friction $\left(\mu \right)$ between the surfaces, changes with time $t$ as the body moves along the surface through different points as shown in graph $\left(g=10 \mathrm{m} {\mathrm{s}}^{–2}\right).$ Select the correct alternative.

Figure shows a block of mass $m$ resting on a plank of mass $M,$ placed on a smooth horizontal surface. The coefficient of friction between the block and plank is $\mu .$ A horizontal force $F$ is applied on the plank which varies with time $t$ as $F=kt$ ($k$ is a positive constant). Select the correct alternative.

Statement $\mathrm{I}$ : A cloth covers a table. Some dishes are kept on it. The cloth can be pulled out without dislodging the dishes from the table

Statement $\mathrm{II}$ : For every action there is an equal and opposite reaction.