Capillary Action - Height of A Meniscus

Height of A Meniscus

The height h of a liquid column is given by:

where is the liquid-air surface tension (force/unit length), θ is the contact angle, ρ is the density of liquid (mass/volume), g is local gravitational field strength (force/unit mass), and r is radius of tube (length).

For a water-filled glass tube in air at standard laboratory conditions, γ = 0.0728 N/m at 20 °C, θ = 20° (0.35 rad), ρ is 1000 kg/m3, and g = 9.81 m/s2. For these values, the height of the water column is

Thus for a 4 m (13 ft) diameter glass tube in lab conditions given above (radius 2 m (6.6 ft)), the water would rise an unnoticeable 0.007 mm (0.00028 in). However, for a 4 cm (1.6 in) diameter tube (radius 2 cm (0.79 in)), the water would rise 0.7 mm (0.028 in), and for a 0.4 mm (0.016 in) diameter tube (radius 0.2 mm (0.0079 in)), the water would rise 70 mm (2.8 in).

Read more about this topic:  Capillary Action

Famous quotes containing the words height of a, height of and/or height:

    It would be naive to think that peace and justice can be achieved easily. No set of rules or study of history will automatically resolve the problems.... However, with faith and perseverance,... complex problems in the past have been resolved in our search for justice and peace. They can be resolved in the future, provided, of course, that we can think of five new ways to measure the height of a tall building by using a barometer.
    Jimmy Carter (James Earl Carter, Jr.)

    The enemy are no match for us in a fair fight.... The young men ... of the upper class are kind-hearted, good-natured fellows, who are unfit as possible for the business they are in. They have courage but no endurance, enterprise, or energy. The lower class are cowardly, cunning, and lazy. The height of their ambition is to shoot a Yankee from some place of safety.
    Rutherford Birchard Hayes (1822–1893)

    It will be seen that we contemplate a time when man’s will shall be law to the physical world, and he shall no longer be deterred by such abstractions as time and space, height and depth, weight and hardness, but shall indeed be the lord of creation.
    Henry David Thoreau (1817–1862)