A box containing supplies is vertically lowered at constant speed by a rope from a hovering helicopter. Consider the following forces that arise in this situation:

force 1: the force of the earth pulling on the box
force 2: the tension force acting on the box
force 3: the force of the earth pulling on the helicopter
force 4: the force of the box pulling on the Earth
Which two forces when added together give the net force on the box?