Jaguar pilot said:
The water level will in fact go up, since the anchor is more dense that water. Basic Archimedes stuff. Before the anchor was dropped the floating boat experienced an upthrust equal to the weight of water displaced.
Come on lad. The water level will drop. It's been unanimous since you got here. Either you didn't read any of the above posts or you're just a stirrer!!
As for the birds flying in a plane (and this has been done before) the plane wouldn't stay straight and level. 'Every action...' and all that. The act of the birds jumping into the air at the same time (they can't fly from a stand-still, just like us
) will cause the plane to momentarily weigh more. Try standing on a scales. It'll read your weight. Now try jumping from the scales. The needle will swing massively. Of course if the plane was trimmed properly it should get back to straight and level after everything settled down, I should think.