A device used to measure the specific gravity of a liquid is called a hydrogmeter. In a simple hydrometer there is a cylindrical galss tube with some lead-weight at its bottom. The device floats in liquid while remaining vertical. The top part of the tube extends above the liquid and the divisions marked on the tube allows one to directly read the specific gravity of the liquid.

The scale on the tube is calibrated such that in pure water it reads 1.0 at the water surface and a lenght `z_(0)` of the tube is submerged. calculate the specific gravity of the liquid if the liquid level is `DeltaZ` above the 1.0 mark. Disregard the curvature of the tube bottom.

Answer

`(z_(0))/(z_(0)+Deltaz)`