Why are most organelles surrounded by membranes

Organelles are usually surrounded by membranes to keep them in one specific area, and they exist to make sure that a particular function can be carried out. They include things like the nucleus - the brain of the cell which sends out all the orders - or mitochondria , the 'power houses' of the cell, which produce energy in the form of ATP .

not too sure thinking all accelerations are pointed down

force required to detach it is given by

charges are taken to be fundamental charge

now we have

so above is the minimum distance at which it will detach