How does friction act as an unbalanced force for objects in motion?

Friction is a force that acts in a direction opposite to motion. If there were not force of friction, a baseball player would never stop and would be continuously moving in the direction of motion. Balanced forces do not cause a nonmoving object to start moving.

The first step of the STOP procedure is S, which stands for "stop." This indicates that you should stop what you're doing to place your full attention on the situation at hand. This will allow you to stay focused on what's specifically happened to an athlete.