What happens to a wet sponge when you aim a fan at it? Water leaves the sponge faster than one sitting in still air. Temperature and surface area also play a role.
You test each factor one at a time. Use sponges of different sizes to change surface area. Use hot and cold water to change temperature. Use a fan to add wind. A pan balance tracks how much water each sponge loses.
The key rule is to change only one factor at a time. Everything else stays the same so the test is fair.
Liquid water turns into gas and moves into the air — that process is evaporation. Three factors control how fast it happens: temperature, wind, and surface area. When you aim a fan at a wet sponge, the moving air carries water vapor away faster than still air does. Hot water leaves a sponge faster than cold water, and a larger sponge exposes more surface for water to escape from.
How much outside space a wet object exposes to the air affects how fast water leaves it. When you use sponges of different sizes, you change that exposed area. Temperature and wind are tested the same way — one factor changes while everything else stays the same. A pan balance tracks how much water each sponge loses, showing that temperature, wind, and the size of the sponge all affect how fast water evaporates.
You will need a pan balance, sponges of different sizes, scissors, a plastic sandwich bag, a spotlight, hot and cold water, an electric fan, and a jar lid.
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The results of the experiment showed that temperature, wind, and surface area all had an effect on the rate of evaporation. The most significant factor was temperature, with the highest rate of evaporation occurring when the water was the hottest.
Why do this project?
This science project is interesting because it shows how different factors can affect the rate of evaporation.
Also Consider
Experiment variations to consider include testing the effects of humidity and air pressure on the rate of evaporation.
Full project details
Additional information and source material for this project are available below.
