As many of us know Iron Man 3 has made its debet earlier this month and has many new and exciting aspects of physics in it. One scene in the movie is of Tony Stark's house being blown up by helicopters. The really exciting part isn't the house bursting into flames, but when Tony is being dragged down to the ocean floor by debre from the house. This got me thinking, would Tony and the Iron Man suit sink on its own or stay afloat?
In order to stay afloat or have neutral bouyancy, the suit would have to have a density of at least 1 because that is the desity of water. If the desity of an object is exactly 1 it will be neutral in bouyancy. This means that the object will not sink nor float unless acted on by an outside force. With a density of more than 1 the object will sink. The greater the density the more eager the object will be to sink to the bottom. The same goes for densities less than 1.
Being made of different types of alloys and metal the Iron Man suit will most deffinetly have a desity of more than one. So on its own with Tony in it, he would sink to the bottom....
However this could be overcome with ballast tanks. By regulating the amount of water in these tanks the density of the object with the tanks changes. This is how submarines submerge and return back to the top. Knowing the limitless boundries of Tony Stark the capabilities of Iron Man could very well include submersion.