A boy and a girl tight two cords to a ring and play to find out who is stronger. The boy grab one of the cords and exert a force of 11 N, the girl applies 13 N at the same time. If both pull the cords on different directions... Who will win?
Fchico = 11 N
FR = ?
Thus the forces exerted are concurrent and are applied on the same direction but opposite sense, both can be replaced by one and only resultant force. That force has the same direction than the bigger one. On this case:
FR = | Fboy - Fgirl |
That means the equivalent situation is as the boy doen´t pull the cord and she would pull with a force of 2 N. So, the girl wins.