If a ladder weighing $250\,N$ is placed against a smooth vertical wall having coefficient of friction between it and floor is $0.3$, then what is the maximum force of friction available at the point of contact between the ladder and the floor ........ $N$

A block of mass $5\, kg$ is kept on a rough horizontal floor. It is given a velocity $33\, m/s$ towards right. A force of $20\sqrt {2\,} \,N$ continuously acts on the block as shown in the figure. If the coefficient of friction between block and floor is $0.5$ the velocity of block after $3\, seconds$ is ........ $m/s$  ($g = 10\, m/s^2$)

A rectangular box lies on a rough inclined surface. The coefficient of friction between the surface and the box is $\mu $. Let the mass of the box be $m$.

$(a)$ At what angle of inclination $\theta $ of the plane to the horizontal will the box just start to slide down the plane ?

$(b)$ What is the force acting on the box down the plane, if the angle of inclination of the plane is increased to $\alpha > \theta $ ?

$(c)$ What is the force needed to be applied upwards along the plane to make the box either remain stationary or just move up with uniform speed ?

$d)$ What is the force needed to be applied upwards along the plane to make the box move up the plane with acceleration $a$ ?

When two surfaces are coated with a lubricant, then they

Maximum value of static friction is called

What is the maximum value of the force $F$ such that the block shown in the arrangement does not move ....... $N$