Underwater submersibles must match the local density in order to remain neutrally buoyant. Maximum dive depths for large submarines are around 500 m, where the pressure is roughly 50 bar and the temperature is close to 20 C. What fractional change in the density of water would a submersible experience between 1.0 bar (i.e., roughly at the ocean surface) and 50. bar for a fixed temperature of 20.C? What fractional change in (absolute) temperature (from 20.C) would be required to cause the density of water at 50.bar to be the same as its density at 1 bar and 20 C.