A block of mass $m$ rests on a rough inclined plane. The coefficient of friction between the surface and the block is $\mu$. At what angle of inclination $\theta$ of the plane to the horizontal will the block just start to slide down the plane?
$\theta = \tan^{-1} \,\mu$
$\theta = \cos^{-1} \,\mu$
$\theta = \sin^{-1} \,\mu$
$\theta = \sec^{-1} \,\mu$
Impending relative motion is opposed by which type of friction ?
Two balls of masses ${m_1}$ and ${m_2}$ are separated from each other by a powder charge placed between them. The whole system is at rest on the ground. Suddenly the powder charge explodes and masses are pushed apart. The mass ${m_1}$ travels a distance ${s_1}$ and stops. If the coefficients of friction between the balls and ground are same, the mass ${m_2}$ stops after travelling the distance
Which of the following is self adjusting in nature?
A block of mass $0.1 \,kg$ is held against a wall by applying a horizontal force of $5\, N$ on the block. If the coefficient of friction between the block and the wall is $0.5$, the magnitude of the frictional force acting on the block is ........ $N$
A block of mass $5\, kg$ is on a rough horizontal surface and is at rest. Now a force of $24\, N $is imparted to it with negligible impulse. If the coefficient of kinetic friction is $0.4$ and $g = 9.8\,m/{s^2}$, then the acceleration of the block is ........ $m/s^2$