1. No Change in Motion:
- The object in question remains at rest (static equilibrium) or moves with constant velocity (dynamic equilibrium).
- This means there is no acceleration.
2. Equal and Opposite Forces:
- All the forces acting on the object cancel each other out.
- This means the net force is zero.
Here's how to determine if forces are balanced:
* Identify all the forces: Draw a free-body diagram showing all the forces acting on the object.
* Determine the direction of each force: Label each force with an arrow indicating its direction.
* Consider the magnitudes of the forces: If the forces are equal in magnitude and opposite in direction, they are balanced.
* Calculate the net force: Sum up the forces in each direction. If the net force is zero, the forces are balanced.
Example:
Imagine a book sitting on a table. The book is at rest, so we know the forces are balanced.
* Forces acting on the book:
* Gravity (downward)
* Normal force from the table (upward)
* Balanced forces:
* Since the book isn't moving, the force of gravity and the normal force must be equal in magnitude and opposite in direction.
Key Point: Balanced forces do not mean there are no forces acting on the object, but rather that the forces cancel each other out, resulting in no net force.
