A light string passing over a smooth light pulley connects two block of masses $m_1$ and  $m_2$ (vertically). If the acceleration of the system is $\left( {\frac{g}{8}} \right)$, then the ratio of masses is

An insect crawls up a hemispherical surface very slowly (see the figure). The coefficient of friction between the insect and the surface is $1/3$. If the line joining the centre of the hemispherical surface to the insect makes an angle $\alpha $ with the vertical, the maximum possible value $\alpha $ is given by

A person in an elevator accelerating upwards with an acceleration of $2\,ms^{-2}$ , tosses a coin vertically upwards with a speed of $20\,ms^{-1}$ . After how much time will the coin fall back into his hand ? $(g = 10\,m s^{-2})$

A block of mass $m$ lying on a rough horizontal plane is acted upon by a horizontal force $P$ and another force $Q$ inclined an at an angle $\theta$ to the vertical. The minimum value of coefficient of friction between the block and the surface for which the block will remain in equilibrium is :

A monkey of mass $20\,kg$ is holding a vertical rope. The rope can break when a mass of $25\,kg$ is suspended from it. What is the maximum acceleration with which the monkey can climb up along the rope?

Select correct statement regarding pseudo force