A demeaning quote from one of High plains other enlightening threads on the same subject.
And to determine if you are physics challenged, perhaps this simple problem would give insight.
An ship full of iron-ore floats into a lock used to change water levels on a river. After both lock doors are closed and the lock fills with water, the ship suddenly sinks to the bottom of the lock. Does the level of the water in the lock
a.) go up?
b.) go down?
c.) stay the same?
Figure out the above Bob and I will see if it is worthwile trying to explain "How?"
Ed S