When balanced forces act on an object that is moving, the object will continue to move at a constant speed in a straight line.

Here's why:

* Balanced forces: This means the forces acting on the object are equal in magnitude and opposite in direction.

* Newton's First Law of Motion: This law states that an object at rest will stay at rest, and an object in motion will stay in motion at a constant velocity unless acted upon by a net force.

Since the forces are balanced, there's no net force acting on the object. This means the object's motion is not being changed. It will continue moving at the same speed and in the same direction.