Question

A hydrometer is a device used to measure the density of a quid. It is a cylindrical tube weighted at one end, so that it floats with the heavier end downward. The tube is contained inside a large medicine dropper," into which the dis drawn using the squeeze bulb (see the drawing). For use with your car, marks are put on the tube so that the level at which it oats indicates whether the liquid is battery acid (more derse) or antifreeze (less dense). The hydrometer has a weight of W = 6.09 10 N and a cross-sectional area of A = 6.84 x 10 m. How far from the bottom of the tube should the mark be put that denotes (a) battery acid (p = 1280 kg/m) and (b) antifreeze 1073 kg/m)? Hydrometer Marks for two types of (b) h-

Answer 1

@ For Acids : At floating depth forces on the tube balenced. up thrust force cu) = weight = 0.9609N uz weight of liquid displaced I . u = A x L x P x 9.8 given a A= 6 848 10s P = 1280 kg / m3 600. 6.094 102 U LE AxPxq8 6.848 108 x 1280 x 98 [h=7609 com]

© For antifreeze P = 1073 6109x102 u. L = AX PX 9.8 6.84x 10 x 1073 x 9.8 L 8.46cm