This is the formula for a thick vertically faulted slab with such a large throw that the downthrow side makes no contribution to the gravitational force .
The governess disappeared soon after this, and although investigations have been carried out, and advertisements placed in newspapers, and every effort made to find her, nobody knows where she's gone.
Previously the government had said almost twice as many people were unaccounted for but on Thursday after comparing information from different records officials revised their count.