$A$ book is lying on a table. What is the angle between the normal reaction acting on the book on the table and the weight of the book (in $^\circ$)?

Why are the states of a body at rest and a body moving with constant velocity considered equivalent in terms of net force?

$A$ mass '$M$' is suspended by a rope from a rigid support at point '$P$' as shown in the figure. Another rope is tied at end '$Q$' and pulled horizontally with a force '$F$'. If the rope makes an angle '$\theta$' with the vertical,then the tension in the string '$PQ$' is

$A$ stone of mass $0.05 \,kg$ is thrown vertically upwards. What is the direction and magnitude of the net force on the stone during its upward motion?

$A$ rod $(AB)$ is attached to a fixed point $(C)$ using a light rope $(AC)$. The other end of the rod $(B)$ is resting on ice with negligible friction,and the system is in a stationary position. Which of the following can be the equilibrium configuration of this system?

$A$ $50 \, kg$ homogeneous smooth sphere rests on a $30^{\circ}$ incline $A$ and bears against a smooth vertical wall $B$. Calculate the contact force at $A$. (Take $g = 10 \, m/s^2$)