A cylindrical fishing float is 15cm long, with an average cross section of 3cm^2. It is made of polystyrene and has negligible mass. A lead weight of 30g is attached to the bottom of the float using a thin nylon monofilament line. Question: Calculate how far the float will sink into the water. Treat g as equal to 10N kg-1 I know Archimedes said upthrust acting on a body is equal to weight of fluid displaced but can't see how to apply that in this case. Thanks for any help.