What is a Balanced Force?
The balanced force is the term that can be heard a lot while dealing with physics. But before we know about the balanced force, we must understand what we mean by force.
Force is the driving factor of almost every phenomenon in the universe. It can be defined as the pull or push, which is applied to an object. In nearly every aspect of our day-to-day life, either we apply force or force is applied to us. From the solar system where the gravitational pull of the sun binds every element together to the lifting a toy by a child, force is everywhere.
Newton’s First Law says a body at rest or in motion will continue to remain in the fixed position unless an external force is applied to it. This means only if forces not applied on an object, its velocity will stay constant. The only way to change its velocity is to apply a force. Therefore force is very vital.
However, if you push a shopping cart and let it go, it doesn’t keep going forever at a constant velocity. It will stop after a while. There is a role of friction. The friction the ground surface has applies a force on the shopping cart to slow it down to a stop.
If you consider the condition in space, there is less friction and air resistance. If an astronaut throws a ball in space, it keeps going as there are no forces on the ball.
Now let’s try to find out in detail what balanced force actually is.
Balanced forces are where two forces of equal size act on an object in opposite directions. It means that in each direction, any pushes and pulls are balanced by another force in the opposite direction. In a balanced force, a body or an object continues to be in its position, i.e., it may stay still in its position or continues to move in the same direction at the same speed.
It is important to note that an object can be in motion even if no forces are acting on it. Balanced force is equivalent or identical to no force at all. Balanced force is, therefore, equal to no acceleration. When the force becomes unbalanced, the object will either accelerate or decelerate.
Characteristics of Balanced Force
- Balanced forces have equal magnitude.
- Balanced forces are of equal size.
- Balanced forces work on an object in opposite directions.
- In balanced forces, the state of rest or motion of an object doesn’t change.
- Balanced forces don’t allow an object in motion to change its direction or speed.
- In balanced forces, the net forces acting is zero.
5 Brilliant Examples of Balanced Forces
Let us look at the following examples for understanding the balanced force better.
1. Pushing against a wall
Suppose a man is pushing against the wall. But neither the wall moves nor do you. It means the forces at play balance each other, and the force both the man and the wall are exerting on each other is a balanced force as a result of which the wall doesn’t move.
2. A game of tug of war with equally matched opponents
In a game of tug-of-war between two equally matched teams, neither of the teams is able to pull the opposing team towards itself. This means each team is exerting a balanced force on each other as a result of which none of the sides is moving towards the other side.
3. A book lying on a table
Two vertical forces are acting on the book, force of gravity and the normal force of the table. Gravity is pulling the book down, and the table is pushing it up. The force of gravity is balanced by the table’s normal force. If the table is removed from under it – the force of gravity is no longer ‘balanced’ by the upward force of the table and, therefore, the book accelerates down.
Similarly, when we hold a football on our hand, two forces are acting simultaneously on the football. One force applied by the person’s hand that works vertically upwards and the other is gravity that acts vertically downwards and balances each other. As a result, the effect of one force is being canceled by the other forces.
4. Running of a vehicle at uniform velocity
When a vehicle runs at uniform velocity on a rough level road, its weight is balanced by the normal force of the road. The force of the vehicle that is directed forward is balanced by the friction of the road and its tires.
5. Sitting on a chair
When one sits down, the system is in balance. Here the downward force exerted by gravity (weight) is exactly counteracted and balanced by the normal upward force of the chair. As long as the system is not moving, the forces are balanced as per Newton’s Second Law of Motion.
Other Examples of Balanced Force
1. A heavy fruit is attached to the stem of the tree because its weight is balanced by the upward force of the stem.
2. A washed shirt on a hanger remains attached to a stretched steel wire. The weight of the shirt is balanced by the tension of the cable, which is the slight force of the wind that is balanced by the friction of the air surrounded.
3. The force of the light wind that passes from an electric fan is balanced by friction.
How can Balanced Forces be Demonstrated?
Balanced forces can be demonstrated in the objects in hanging position, floating position, and standing/sitting position.
1. Objects in hanging position
If you look at a hanging glass bulb shade, you will see that the weight of the glass bulb shade pulls down, and the tension in the cable holding the bulb shade pulls up. Here the forces pulling down and pulling up are in balance.
2. Objects in the floating position
Consider a log floating in a pool of water. The log floats because the weight of the log is balanced by the upthrust from the water. If more weight is put on the log, the force that pulling it down may be more than the force pushing the log upward and will cause it to sink.
3. Objects standing/sitting on a surface
Suppose a metal block is resting on a surface of a table. The weight of the metal block is balanced by the reaction force from the surface. The surface pushes up against the metal block, and balance out the weight or force of the metal block.