1. Acceleration:

* Net force: Unbalanced forces create a net force, which is the overall force acting on an object. This net force is what determines the object's acceleration.

* Newton's Second Law: This law states that the acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass. In simpler terms, a larger net force means a larger acceleration, and a heavier object will accelerate less than a lighter one under the same force.

* Change in speed: Acceleration means a change in speed or direction. An unbalanced force will either increase the object's speed (if the force is in the direction of motion) or decrease its speed (if the force is opposite to the direction of motion).

2. Examples:

* Pushing a box: Pushing a box across a floor creates an unbalanced force, causing it to accelerate and increase its speed.

* Braking a car: Applying the brakes creates an unbalanced force that slows the car down, decreasing its speed.

* Throwing a ball: The force of your throw creates an unbalanced force, causing the ball to accelerate and gain speed.

In summary:

Unbalanced forces cause objects to accelerate, resulting in a change in their speed (either increasing or decreasing) and possibly their direction as well. This acceleration is directly determined by the magnitude and direction of the net force, as well as the object's mass.