A liquid is used to make a mercury-type barometer. The barometer is intended for spacefaring astronauts. At the surface of the earth, the column of liquid rises to a height of 2185 mm, but on the surface of Planet X, where the acceleration due to gravity is one-fourth of its value on the earth, the column rises to only 725 mm. Find the (a) the density of the liquid, (b) the atmospheric pressure at the surface of Planet X.