$A$ man of mass $50 \,kg$ carries a bag of weight $40 \,N$ on his shoulder. The force with which the floor pushes up his feet will be ......... $N$.

When an object is in equilibrium state,then

$A$ book of mass $5 \,kg$ is placed on a table and it is pressed by $10 \,N$ force. Then,the normal force exerted by the table on the book is ......... $N$.

Three forces $\vec{P}, \vec{Q},$ and $\vec{R}$ act at a point in a plane. The angles between $\vec{P}$ and $\vec{Q}$,and $\vec{Q}$ and $\vec{R}$ are $150^{\circ}$ and $120^{\circ}$ respectively. What is the ratio of the magnitudes of the forces $\vec{P}, \vec{Q},$ and $\vec{R}$ if the system is in equilibrium?

$A$ particle moving with velocity $\overrightarrow{V}$ is acted upon by three forces represented by the vector triangle $PQR$. The velocity of the particle will

$A$ mass of $10 \, kg$ is suspended vertically by a rope of length $5 \, m$ from the roof. $A$ force of $30 \, N$ is applied at the middle point of the rope in the horizontal direction. The angle made by the upper half of the rope with the vertical is $\theta = \tan^{-1}(x \times 10^{-1})$. The value of $x$ is ................
(Given $g = 10 \, m/s^2$)