2.3.9. Droplets and Surface Tension

Try these first

1. 1.

   What is surface tension?

   Hint

   Think about how rainwater beads on a smooth surface.

2. 2.

   Define capillarity.

   Hint

   Consider how water rises in a straw.

3. 3.

   What is surface tension?

   • A force that holds molecules together
   • The weight of a droplet
   • A type of buoyancy

   Hint

   Consider how water beads up instead of spreading out.

4. 4.

   True or False: Surface tension decreases with increasing temperature.

   • True
   • False

   Hint

   Think about how heat affects the behavior of water.

5. 5.

   A water droplet of radius 1 cm is split into 100 smaller droplets. Calculate the work done if the surface tension is 0.072 N/m.

   Hint

   Consider the initial and final surface areas of the droplets.

6. 6.

   How would the height of liquid in a capillary tube change if the diameter of the tube is reduced by half?

   Hint

   Think about the relationship between radius and capillary rise.