Can anyone tell me if magnetic power is additive or something else? If I have a flat magnetic sheet and I add a second sheet does the magnetic attraction to surrounding objects double?
I don't know if it's an exact 1-to-1 increase, but I've seen instances where adding multiple identical magnets increases the magnetic field. For example, we have products which use a magnet to trip a reed switch. In testing of a new product it was found that the magnet initially specified didn't reliably trip the reed, but adding multiple magnets achieved the desired result without decreasing the spacing between the reed and the magnet.
If two magnets have a pull of 2 lbs ea., then two of them side by side can lift 4 lbs, since they act independently, just like suction cups.
One magnet behind another will not multiply attractive force proportionately. If this were true then longer magnets would be proportionately more powerful than shorter ones, which is not the case.
And remember that magnetic sheets are not really true magnets like solid ones, with a north and south pole. They have been magnetized in spots on the surface with alternating N and S areas.