In the figure, a block of weight $60\, N$ is placed on a rough surface. The coefficient of friction between the block and the surfaces is $0.5$. ........ $N$ should be the maximum weight $W$ such that the block does not slip on the surface .
$60$
$\frac{{60}}{{\sqrt 2 }}$
$30$
$\frac{{30}}{{\sqrt 2 }}$
A block of mass $m$ is stationary on a rough plane of mass $M$ inclined at an angle $\theta$ to the horizontal, while the whole set up is accelerating upwards at an acceleration $\alpha$. If the coefficient of friction between the block and the plane is $\mu$, then the force that the plane exerts on the block is
A force of $19.6\, N$ when applied parallel to the surface just moves a body of mass $10 \,kg$ kept on a horizontal surface. If a $5\, kg$ mass is kept on the first mass, the force applied parallel to the surface to just move the combined body is........ $N.$
A block of mass $2\,kg$ moving on a horizontal surface with speed of $4\,ms ^{-1}$ enters a rough surface ranging from $x =0.5\,m$ to $x =1.5\,m$. The retarding force in this range of rough surface is related to distance by $F =- kx$ where $k =12\,Nm ^{-1}$. The speed of the block as it just crosses the rough surface will be ........... $\,ms ^{-1}$
A block of mass $2 \,kg$ rests on a rough inclined plane making an angle of $30°$ with the horizontal. The coefficient of static friction between the block and the plane is $ 0.7$. The frictional force on the block is ....... $N$.
A boy of mass $4\, kg$ is standing on a piece of wood having mass $5 \,kg$. If the coefficient of friction between the wood and the floor is $0.5,$ the maximum force that the boy can exert on the rope so that the piece of wood does not move from its place is ......$N.$(Round off to the Nearest Integer) [Take $g=10 \,ms ^{-2}$ ]