• Question: How do the really big ships that carry lorries and veachiles float on water all though they are hundreds of tonnes ????

    Asked by summer8181 to David, Luna, Mark, Melanie, Probash on 24 Mar 2011 in Categories: .
    • Photo: Luna Munoz

      Luna Munoz answered on 24 Mar 2011:

      It’s the design of the ship. In order to carry a heavy load the bottom of the ship that is typically submerged must be wide enough so that the ship stays upright. I went to see the ship (the Wasa) that sunk in the Baltic Sea in 1628 and the hull was very narrow. It had been designed to hold a certain weight – for the people on board – but they added many more cannons than planned and it just tipped on its maiden voyage.

    • Photo: David Pyle

      David Pyle answered on 24 Mar 2011:

      Archimedes worked this one out a few years ago. Basically, as long as the mass of the object is less than the mass of water displaced by the object, then it will float. So ships have a big surface area of hull which comes into contact with the water – and this helps to displace large amounts of water.

    • Photo: Probash Chowdhury

      Probash Chowdhury answered on 24 Mar 2011:

      It’s all in the shape of the hull. The bigger the ship usually the wider they are too. This helps them to trap more air inside which helps them to stay afloat.