One method of measuring the density of a liquid is illustrated in the figure. One side of the
U-tube is in the liquid being tested, and the
other side is in water of density 1000 kg/m3
.
The air is partially removed at the upper
part of the tube and the valve is closed. The
height of the water above its pool surface is
0.81 m . The height of the liquid above its
pool surface is 0.45 m . The difference in the
heights of the pool surfaces is 0.21 m .
find the density of the liquid in kg/m^3