A U-shaped tube open to the air at both ends contains water. A quantity of oil of unknown density is slowly poured into the right arm of the tube until the vertical height of the oil column is 20cm. The top of the oil is 8cm higher than the top of the water. Find the density of the oil.

Scientist have use computer models to create a series of maps that show how susceptible coastal cities in island countries are to the sea rising at different levels.the map shows that a 1 meter rise would swap cities all along the us eastern seaboard. a 6-meter sea level rise with sub merge a large part of florida. thermal expansion has already raise the oceans 10 to 20 centimeters the most likely cause,directly and indirectly, for such a rise in sea level is