Can You Blow Out a Candle From Afar Using Shockwave Principles?
Materials in the box
1. One jumbo plastic cup with a pre-drilled hole in the bottom
2. Three balloons
3. A tealight candle
Materials from your house
1. Scissors
2. Matches
How do I begin?
1. Cut about 1/3 the bottom of one of the balloons. You may need to cut off a little more, depending on how the balloon fits across the mouth of the plastic cup.
2. Tie the mouth of the balloon into a knot. If you like, you may tie a piece of string to it, so it is easier to pull. The knot has a tendency go inwards.
3. Now stretch the cut balloon across the mouth of the plastic cup, with the knotted end sticking out.
4. Place the tealight on a table/ counter/ any flat surface and light it.
5. Stand about one foot away at first and use the knotted end of the balloon to pull back. Now aim at the candle and let the ballloon go.
6. A blast of air gushes out moves / extinguishes the candle.
What just happened?
When you pull on the balloon's knotted tip, it creates a shock wave in the air. This shockwave flows in the direction of the candle, extinguishing the flame. Earthquakes release tremendous amounts of energy that can cause seismic waves. These are also called shock waves but earthquake shock waves travel through the earth. Shock waves that flow through Earth are also invisible but have an effect on the things they contact. The shock wave in this experiment can also be called a sound wave. When the shock wave hit your eardrums, it moves / vibrates them just as it moves the candle flame, causing you to hear the thumping sound. Vibrations need a medium like air to travel to produce sound that finally reaches our ears.
Exploring Further
1. Try standing closer this time and pull the knotted balloon tip again.
2. Try standing at about 3 feet away and pull the knotted balloon tip again.