$A$ car is moving with uniform velocity on a rough horizontal road. Therefore,according to Newton's first law of motion,

On a stationary sail-boat,air is blown at the sails from a fan attached to the boat. The boat will

$A$ body of mass $3 \, kg$ hits a wall at an angle of $60^\circ$ with the wall and returns at the same angle. The speed of the body is $10 \, m/s$ and the impact time is $0.2 \, s$. Calculate the force exerted on the wall.

$A$ system consists of three masses $m_1, m_2$ and $m_3$ connected by a string passing over a pulley $P$. The mass $m_1$ hangs freely and $m_2$ and $m_3$ are on a rough horizontal table (the coefficient of friction $= \mu$). The pulley is frictionless and of negligible mass. The downward acceleration of mass $m_1$ is (Assume $m_1 = m_2 = m_3 = m$)

Three forces acting on a body are shown in the figure. To have the resultant force only along the $y-$ direction,the magnitude of the minimum additional force needed is ........... $N$.

$A$ block of mass $m$ is lying on a rough inclined plane having an inclination $\alpha = \tan^{-1}(\frac{1}{5})$. The inclined plane is moving horizontally with a constant acceleration of $a = 2 \text{ ms}^{-2}$ as shown in the figure. The minimum value of the coefficient of friction,so that the block remains stationary with respect to the inclined plane,is (Take $g = 10 \text{ ms}^{-2}$):