Two masses $m_1 = 5 \ kg$ and $m_2 = 10 \ kg$,connected by an inextensible string over a frictionless pulley,are arranged as shown in the figure. The coefficient of friction of the horizontal surface is $0.15$. The minimum mass $m$ that should be placed on top of $m_2$ to stop the motion is ........ $kg$. (in $.3$)

$A$ force $F$ is applied on the top of a cube as shown in the figure. The coefficient of friction between the cube and the ground is $\mu$. If $F$ is gradually increased,the cube will topple before sliding. Then the range of $\mu$ is:

Two pulley arrangements shown in the figure are identical. The mass of the rope is negligible. In figure $(a)$,the mass $m$ is lifted by attaching a mass $2m$ to the other end of the rope. In figure $(b)$,$m$ is lifted up by pulling the other end of the rope with a constant downward force $F = 2mg$. The accelerations of $m$ in the two cases are respectively:

$A$ bouncing ball of mass $200 \,g$ falls from a height of $5 \,m$ onto a horizontal ground. After every impact with the ground, the velocity of the ball decreases by $\frac{1}{2}$ times. The total momentum the ball imparts to the ground after $3$ impacts is (Let $g=10 \,m/s^2$):

For the given system,find the value of ${\theta _1}$ in degrees.

Identify the incorrect statement.