1. The problem statement, all variables and given/known data Estimate the density of the water 5.7 km deep in the sea. (bulk modulus for water is B=2.0 x 10^9 N/m^2) By what fraction does it differ from the density at the surface? 2. Relevant equations P=(rho)gh=F/A=B(delta l/l) 3. The attempt at a solution So I have several equations above. I wanted so solve for rho using the first equation but I don't know pressure. I tried the second equations but I don't know Force or area. I tried the last equation but I would need delta l and l so basically I'm stuck. Some advice would be much appreciated.