$A$ plank with a box on it at one end is gradually raised about the other end. As the angle of inclination with the horizontal reaches $30^o$,the box starts to slip and slides $4.0\, m$ down the plank in $4.0\, s$. The coefficients of static and kinetic friction between the box and the plank will be,respectively:

$A$ block placed on a rough inclined plane of inclination $\theta = 30^{\circ}$ can just be pushed upwards by applying a force $F$ as shown. If the angle of inclination of the inclined plane is increased to $\theta = 60^{\circ}$,the same block can just be prevented from sliding down by application of a force of the same magnitude $F$. The coefficient of friction between the block and the inclined plane is:

The curve between net force and time is shown. Initially,the particle is at rest. Which of the following best represents the resulting velocity-time graph of the particle?

$A$ car of mass $1250 \ kg$ is moving with a velocity of $30 \ m/s$. $A$ resistive force of $750 \ N$ acts on it. If the engine produces a power of $30 \ kW$,what is the acceleration of the car in $m/s^2$?

The driver of a car travelling at velocity $v$ suddenly sees a broad wall in front of him at a distance $d$. He should

In the figure, two blocks are connected by a uniform strut attached to each block with frictionless pins. Block $A$ weighs $400 \, N$, block $B$ weighs $300 \, N$, and the strut $AB$ weighs $200 \, N$. If $\mu = 0.25$ under block $B$, determine the minimum coefficient of friction under block $A$ to prevent motion.