Wind can evaporate water. Hang out your laundry to dry and the wind is helping. This can show why.

Evaporation in the water cycle

Objectives:

Students see an example of how wind increases evaporation in an experimental format.

Materials:

  • water

  • water spray bottle

  • large cardboard pieces to use to fan and blow wind

  • Items to get wet before fanning with wind : Paper towels or cardboard pieces will work, with a rough surface, like brown packing boxes or paper grocery bags. If using paper towels or absorbent paper they must be fixed to a wall, whiteboard or in some way fixed, as the students are going to blow air onto it.

Focus:

Ask students if their family has ever dried laundry outside. It might make sense to us that the sun dries the clothes, and the sun can warm things up. But does the wind dry things out? Can wind evaporate water?

Procedure:

Draw and define two equally sized areas on the whiteboard area. Fix the bags or papers onto the board in different sides, away from each other. Label one area A and the other B. Spray both areas equally with water from the spray bottle so that all the students agree that they are equally wet. Now have a group of students take turns to use big cardboard pieces to fan and blow air on area A but no one blows on area B. In which area will the water dry fastest?

Conclusions:

Have the students describe conclusions from what they saw in area A and B. What was the only difference between A and B? We made wind on A but not on B, and case A dried faster. Does this help show that wind speeds up evaporation? When the wind is blowing outside what can we know about what is happening to ponds or lakes in your local area? If a person owns a swimming pool, does the wind take away their water? Yes , it does.