Test: Conditions for a Rigid-Body - Civil Engineering (CE) MCQ

The requirement of the third law is important in the equilibrium of the body. Especially the rigid bodies. The rigid body particles are in the equilibrium and are thus facing the forces and to be in the equilibrium they also react and apply the opposite force and thus the third law of Newton.

The summation of the forces needs to be zero. So does the summation of the moments need to zero. But talking about the angles, they not needed to zero. But the forces which are acting at particular angles, must needed to be equal to zero. The basic need of the forces to make the body in equilibrium.

The summation of the forces needs to be zero. So does the summation of the moments need to zero. But talking about the angles, they not needed to zero. But the forces which are acting at particular angles, must be needed to be equal to zero. The basic need of the forces to make the body in equilibrium.

The summation of the forces needs to be zero. So does the summation of the moments need to zero. But talking about the angles, they not needed to zero. But the forces which are acting at particular angles, must need to be equal to zero. The basic need of the forces to make the body in equilibrium.

The net moment of the body is zero that doesn’t mean that the distance between the force and the rotational axis is zero. This means moments caused by different forces cancels out. If this happens there is no motion of the body along with any direction and hence the body is said to be in equilibrium.

The application of the conditions of the equilibrium of the body is valid throughout. This means that the conditions are irrespective of the dimensions. The conditions are the basic rules that define the equilibrium of the body and thus are applicable in any dimension of the real axis.

The net force of the body is zero that doesn’t mean that the force are not being applied to the body at all and hence the body is in equilibrium. The equilibrium is only attained if the net force on the body tends to be equal to zero. Thus the forces cancels out. If this happens there is no motion of the body along any direction and hence the body is said to be in equilibrium.

Principle of Transmissibility:

• According to it if we transmit a force in its line of action without changing its magnitude and direction then there will not be a change in the effect of a force.

Additional Information 
Principle of Independence of force:

• It is defined as vertical motion does not affect by the movement of horizontal motion.

Principle of resolution of forces:

• The algebraic sum of the resolved parts of a number of forces in a given direction is equal to the resolved part of their resultant in the same direction.

Method for the resolution for the resultant force:

• Resolve all the forces horizontally and find the algebraic sum of the horizontal components.
• Resolve all the forces vertically and find the algebraic sum of the vertical components.

The resultant of the above both can be given below as,

The resultant force will make an angle with the horizontal can be given as.

The application of the internal forces does affect the conditions of the equilibrium of the body. Not only the external but the internal forces that are developed by the sake of external forces does develop a tending effect on the equilibrium of the body. Thus the internal forces doesn’t cancels out.