To measure the water depth in a large open tank with opaque
walls, an open vertical glass tube is attached to the side of the
tank. The height of the water column in the tube is then used as
a measure of the depth of water in the tank. (a) For a true water
depth in the tank of 3 ft, make use of Eq. 1.22 (with ) to
determine the percent error due to capillarity as the diameter of
the glass tube is changed. Assume a water temperature of 80 F.
Show your results on a graph of percent error versus tube diameter,
D, in the range (b) If you want the
error to be less than 1%, what is the smallest tube diameter allowed?