the-e-dealer Wrote: ------------------------------------------------------- > Almost right. But. actually the arcimedes principle relates to weight. I got my physics o > level! Its not volume! Just noticed hugs explained better than me. Weight of the water displaced, not the weight of the vehicle. As Hugo said, if the vehicle sunk (most likely) you wouldn't know it's weight. The whole 'Eureka' story was that Archimedes knew the weight of the crown (?), but he didn't know its volume. So, he could not calculate the density and therefore decide if it was made of gold or not. But, once he stuck his fat backside in the bath...