If i have two magnets, each rated with 80 lbs of pull power, and place them with opposite poles so that they push apart, what is the amount of weight, or power of the opposing force?
By the way opposite poles ATTRACT (N-S), and same poles REPEL.
The magnitude of the force of attraction/repulsion between two poles is the same but in the opposite direction, for the same distance between the poles.
There is not really enough information to determine the pushing power.
Magnets attract not because "opposites attract" but because their magnetic fields are aligned in the same direction. The full magnetic circuit must be considered when determining the attraction force but the field is reasonably well contained within the loop of ferromagnetic material.
When the magnets are in opposition their fields are highly distorted and forced out of the material so the geometry becomes the main determining factor.
Note also that the width of the gap is very important in both attraction and repulsion as the magnetic permiability of air is only 1/1000 that of typical ferromagnetic materials.
If you were in an experimenting frame of mind you could position one magnet above the other in a glass or plastic tube so that they couldn't move sideways or flip over, and then load weights on the upper magnet until you forced them together. The repulsive force would then be the total of the weights you had added plus the weight of the upper magnet.