How do Temperature and Wind affect Evaporation?

Clouds form in low pressure zones because as hot air rises it carries moisture with it. This moisture is called water vapor and as it cools it forms droplets of water that join together and cause clouds. Most of the water vapor comes from water on earth evaporating and rising with the air. What are some of the things that cause evaporation? How do wind and heat affect how fast water evaporates? This experiment explores the effects of wind and heat on evaporation.

Materials

• 4 kitchen sponges (all the same size)
• Desk lamp or trouble light with an incandescent light bulb (or any bulb that produces heat)
• Water
• An electric fan
• Measuring cup
• A journal to record your findings

Procedure

1. Write down your predictions about which sponges will dry faster and why you think so.
2. Take two of the kitchen sponges and pour exactly the same amount of water on each (make sure that you use enough to completely soak the sponges).
3. Place one of your sponges directly under the desk light (or trouble light) and turn it on with the light source around 8 to 10 inches above the sponge.
4. Place the other sponge somewhere nearby, but away from the heat source.
5. Take the other two sponges and repeat step 1.
6. Place one sponge in front of an electric fan and turn it on.
7. Place the other sponge away from the fan at room temperature.
8. Check on your sponges periodically and record how they are drying. When a sponge is dry, record which sponge dried first and how long it took. Keep checking on the other sponges and record your findings as they dry.

Which sponge dried first? How long did it take? Did heat or wind cause the sponge to dry more quickly? Were your predictions right?