When the forces acting on an object are balanced, its state of motion does not change. According to the provided reference, forces, when balanced, result in an object either remaining at rest (if at rest) or continuing in motion (if in motion) at a constant velocity.
This means that balanced forces do not cause an object to accelerate. Acceleration is a change in speed or direction. If forces are balanced, there is no acceleration.
Understanding Balanced Forces
Balanced forces are forces that are equal in magnitude and opposite in direction, effectively cancelling each other out. When all the forces acting on an object are balanced, the net force acting on the object is zero. A net force of zero is the key condition for the outcomes described above.
Outcome 1: Remaining at Rest
If an object is initially at rest (not moving) and the forces acting on it become balanced, it will continue to remain at rest. It will not start moving.
- Example:
- A book sitting on a table. The force of gravity pulls the book down, and the table exerts an equal and opposite upward force (the normal force). These forces are balanced, so the book remains at rest.
Outcome 2: Continuing in Motion at Constant Velocity
If an object is already in motion and the forces acting on it become balanced, it will continue to move at a constant velocity. Constant velocity means the object moves at a steady speed in a straight line. It will not speed up, slow down, or change direction.
- Examples:
- A car cruising on a level road at a steady 60 mph. If the forward thrust from the engine exactly balances the forces of air resistance and friction, the net force is zero, and the car maintains a constant velocity.
- A spacecraft drifting in deep space, far from any significant gravitational pulls or resistance. Since there are virtually no unbalanced forces acting on it, it continues to move at a constant velocity determined by its initial motion.
Summary of Outcomes
The state of the object when forces are balanced depends solely on its initial state:
| Initial State | Outcome when Forces are Balanced | Description |
|---|---|---|
| At Rest | Remains at Rest | No movement |
| In Motion | Continues at Constant Velocity | Steady speed in a straight line (no change) |
In essence, balanced forces maintain the status quo regarding motion. They do not initiate motion or alter existing motion.
