Many interesting science projects can be done using water balloons, involving concepts such as their resistance to heat, pressure, or relating to the size of splash they create. If you're struggling for topics for an upcoming science project, learning about the different experiments you can do with water balloons can give you ideas. Taking a look at a few options can also spark an idea for an original experiment. Unless otherwise noted, these experiments are suitable for third grade to sixth grade children.
There are many experiments that can be done which relate to the splatter size created by a water balloon. The most basic experiment of this type is to fill up several water balloons so they are the same size, and then drop them from varying heights to determine whether the height a balloon is dropped from has an impact on its splatter size. You will need a ladder (and an adult to drop the balloons) and a tape measure, along with a good supply of balloons to complete this experiment. You can also change the variable to produce an alternative experiment by filling balloons to different volumes, but dropping them from the same height. Measure the splatter size for your results.
Shape and Resistance
For this experiment you can test water balloons of various shapes to see which are more resistant to breakage. Gather several different shapes of balloons and then put them through a stress test. You can do this either by throwing them between two people, at a gradually increasing distance, or by dropping them from gradually increasing heights and seeing which shapes of water balloons are strongest.
Water Balloons vs. Air Balloons: Pressure
This is a test of whether balloons filled with air are more resistant to pressure than balloons filled with water. Buy several balloons from the same manufacturer (ideally use balloons from the same packet) and fill them to a set circumference. Fill half of the balloons with water and half with air. To test the balloons' resistance to pressure, stack books on top of the balloons until they pop. Place a layer of cling film on top of the balloon to protect your books from water. You may need to balance the books with your hand or against a wall. Use the same books to ensure that the same weight is set on each type of balloon. Record the amount of books that can be stacked on before the balloon breaks. The type of balloon which can withstand more books can withstand greater pressure.
Water Balloons vs. Air Balloons: Fire
This experiment requires adult supervision and sets out to investigate whether air-filled balloons or water filled balloons are more resistant to fire. Fill some balloons with air and an equal amount of other balloons with water. Light a candle on a stable surface. Hold the balloons over the flame so that the tip of the flame touches the balloon to discern whether water balloons or air balloons are more resistant to fire. Water balloons are actually considerably more resistant to water, and the water inside them can even boil before the balloon pops. This is why the experiment must be performed by an adult. Remove the balloon from the heat before the water boils.