Balanced forces

Balanced forces

When an object has two forces acting on it that are equal in size but opposite in direction, we say that the forces are balanced.

This is related to the First Law of Motion by Isaac Newton. This law says that an object will keep doing what it is doing, either staying still or moving with the same speed and direction, unless an unbalanced force changes its motion.

This means that if the forces on an object are balanced, the object will not change its speed or direction.

We can use a truck as an example to understand Newton’s first law:

This image depicts a blue truck with labels indicating “Friction” at the front and “Thrust” at the back, used to explain these forces.

Assuming that the forces acting on the truck are balanced:

If the truck was originally moving, then it will continue to move in the same direction and speed.
If the truck wasn’t originally moving, then it will stay still.

Force Diagrams

We can use arrows to show the direction and the size of the force on an object. This is called a force diagram.

This image is a force diagram featuring a cat lying on a table, illustrating the concept of Newton’s third law of motion. It shows the forces acting upon the cat and the table, labeled as “Action” and “Reaction,” respectively.

The diagram above shows that the two arrows have the same length. This means that the cat has two forces that are equal (but in opposite directions).
The length of the arrow shows the size of the force. When the forces are balanced, the total force is zero. This total force is called the resultant force.

Summary:

Balanced forces occur when two forces applied to an object are equal in magnitude but opposite in direction.
Isaac Newton’s First Law of Motion is closely related to the concept of balanced forces.