What are Balanced Forces?
If resultant total of all forces acting on an object is 0, it is called balanced force
Example
A tug of war game in which both teams exert equal force is example of Balanced Force
A stationary object is an example of Balanced force
Explanation
Tug of War Game-Both teams exert Equal Force
In a tug of war game, 2 teams pull rope from opposite direction
If both teams apply equal strength, the rope does not move
This is because force of 2 teams is balanced (one team exert force from left to right and other team exerts equal force from right to left)
Stationary Object is an Example of Balanced force
Suppose a heavy box is kept on ground
It does not move by itself and is stationary
It is because, force of gravity is exerted on box from top to bottom
Also force of reaction is exerted by ground from bottom to top
These both forces balance each other due to which box does not move
Note
Balanced Forces can change shape and size of Object
Example we take inflated balloon and we squeeze it from both sides
It changes shape of balloon
Since we exert force from both sides, it is a balanced force
Hence,we can say that balanced force can change shape and size of object
What are Unbalanced Force?
If resultant total of all forces acting on an object is not 0, it is called unbalanced force
Example
Force Required to Move Stationary Object
Suppose a heavy box is kept on ground
We try to push it with our hands
In this case, if we push it with less force,it does not move (as our muscular force exerted by body is balanced by force of friction)
However, if we push it with more force than the frictional force, it moves because force now is unbalanced force
(as muscular force exerted by our body is more than opposing force of friction)
Force Required to Stop Moving Object
A moving ball stops by itself after some time
it is because force of friction exerts opposite force on object
This force of friction is more than force of ball (force is unbalanced) which brings moving ball to rest
Summary and Difference between Balanced and Unbalanced force
| Balanced Force | Unbalanced force |
| If resultant total of all forces acting on an object is 0, it is called balanced force | If resultant total of all forces acting on an object is not 0, it is called unbalanced force |
| Example | Example |
| Force present in Stationary Object | Force Required to Move Stationary Object |
| Force present in Object moving with constant velocity | Force Required to Stop Moving Object |
| Tug of War Game-Both teams exert Equal Force | Tug of War Game-Both teams exert Equal Force |
| This force cannot move stationary object | This force can move stationary object |
| This force cannot stop moving object | This force can stop moving object |
Questions
NCERT Question 1 - An object experiences a net zero external unbalanced force. Is it possible for the object to be travelling with a non-zero velocity? If yes, state the conditions that must be placed on the magnitude and direction of the velocity. If no, provide a reason.
