How can a force change the motion of an object that is already moving?

They may cause motion to change

Explanation:They may cause motion; they may also slow, stop, or change the direction of motion of an object that is already moving. Since force cause changes in the speed or direction of an object, we can say that forces cause changes in velocity. Remember that acceleration is a change in velocity.

the entire statement is true and correct.  

there's no diagram, nothing is illustrated, and no question is asked.

the higher the current the higher the mag field around it the higher the influence on the compass