1.6. Capillarity and Surface Tension

Try these first

1. 1.

   Define surface tension.

   Hint

   Think about why insects can walk on water.

2. 2.

   What is capillarity?

   Hint

   Consider how liquid moves in a thin straw.

3. 3.

   What causes water to rise in a narrow tube?

   • Gravity
   • Surface Tension
   • Pressure Difference

   Hint

   Recall the straw example.

4. 4.

   True or False: Surface tension affects the ability of insects to walk on water.

   • True
   • False

   Hint

   Think of the critters you see on water's surface.

5. 5.

   A glass tube with a diameter of 5 mm is submerged in water. Calculate the height of the water column that would rise, given the surface tension of water is 0.072 N/m and the contact angle is 0 degrees.

   Hint

   Make sure you use the correct units for density and gravitational acceleration.

6. 6.

   Explain how capillarity affects the way plants obtain water, and why it is vital for their survival.

   Hint

   Think about how tall trees draw water.