9 January 2018

Resultant force definition

What is the resultant force?

resultant force is defined as a total force acting on the body along with their directions. 


On the other words, it is the single force obtained by combining a system of forces acting on a rigid body and it has the same effect on the rigid body as the original system of forces.


The resultant force may be determined by the following laws :


Parallelogram law of forces :


By this law, two forces acting simultaneously on a particle and it can be represented in magnitude and direction by two adjacent sides of a parallelogram, then their results may be represented in magnitude and direction by the diagonal of a parallelogram which passes through their point of intersection. 



Parallelogram law of force

Similar kind of application applicable for triangle, polygon and for similar types of another shape. 


Resultant of two or more intersecting forces found :


Where two or more intersecting forces are found then for solving resultant of that forces steps given below :


Step -1: First of all resolving all the horizontal forces 

Step -2: Then resolving vertical forces 
Step - 3: Then put all data in the below equation and equate. 
Step - 4: Answer will be the resultant force that what we find. 

R = √ ( ∑horizontal force ) 2 + ( ∑vertical force )2

A number of force acting on a particle will be called in equilibrium when :

∑ horizontal force = 0
∑ vertical force = 0

Resultant force for the two forces that are not parallel or any kind of forces :

Step - 1: Draw a free-body diagram of the object.

Step - 2: Draw coordinate axes on the free-body diagram.
Step -3: Decompose the forces acting on the object into x and y components.
Step - 4: Calculate the x and y component of the resultant force by adding the x and y components of all forces.
Step - 5: Find the magnitude and direction of the resultant force by using x and y component. 

Notes :

If the resultant force acting on a stationary object is zero, the object will remain stationary. 

If the resultant force acting on a moving object is zero, the object will carry on moving at the same speed in the same direction.