8.5.1. Forces in Capillary Action

Try these first

1. 1.

   What happens to shear stress in a fluid at rest?

   Hint

   Think about the forces acting on a fluid that is not moving.

2. 2.

   Define gauge pressure.

   Hint

   Consider how pressure is measured from sea level.

3. 3.

   What happens to shear stress in a fluid at rest?

   • True
   • False

   Hint

   Consider the nature of rest.

4. 4.

   Gauge pressure is below atmospheric pressure.

   • True
   • False

   Hint

   Think about how it is measured.

5. 5.

   You have a mercury barometer with a height of 760 mm. Calculate the atmospheric pressure at this height if the density of mercury is 13.6 g/cm^3.

   Hint

   Remember to convert density from g/cm^3 to kg/m^3 and height from mm to m.

6. 6.

   A capillary tube with a diameter of 2mm is placed in water. Calculate the height to which the water will rise if the surface tension of water is 0.072 N/m and the contact angle is 0 degrees.

   Hint

   Make sure to use the density of water, 1000 kg/m^3.