$A$ 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?

The adjoining figure shows a force of $40\, N$ acting at $30^o$ to the horizontal on a body of mass $5\, kg$ resting on a smooth horizontal surface. Assuming that the acceleration due to gravity is $10\, ms^{-2}$,which of the following statements is (are) correct?
$[1]$ The horizontal component of the applied force is $20\sqrt{3}\, N$.
$[2]$ The weight of the $5\, kg$ mass acts vertically downwards.
$[3]$ The net vertical force acting on the body is $30\, N$ (upwards).

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 of $10\,kg$ is suspended vertically by a rope from the roof. When a horizontal force is applied on the rope at some point,the rope deviates at an angle of $45^o$ from the vertical. If the suspended mass is at equilibrium,the magnitude of the force applied is .......... $N$ $(g = 10\,ms^{-2})$.

Define force. What is contact force? Write two examples of field force.

Which of the following sets of three forces acting on a body cannot have a resultant of zero?