Look at the balloons! This was the first week of ScienceDays tutoring here at Duke University. This week, we taught at two local elementary schools, George Watts and EK Powe (Durham Public Schools) at their after school programs! Our lesson this week was about static electricity and how we can use everyday objects to demonstrate common experiences such as the shock you experience when you walk across carpet. We were able to charge these Valentine’s Day balloons with our hair and we also played with combs to demonstrate the polarity of water. Lightning is a dramatic demonstration of static electricity that we occasionally see.
“The static charge in air typically breaks down in this way at around 10,000 volts-per-centimeter (30 kV/cm) depending on humidity. The discharge superheats the surrounding air causing the bright flash, and produces a shock wave causing the clicking sound. The lightning bolt is simply a scaled up version of the sparks seen in more domestic occurrences of static discharge. The flash occurs because the air in the discharge channel is heated to such a high temperature that it emits light by incandescence. The clap of thunder is the result of the shock wave created as the superheated air expands explosively.”
So that is a cool example of how static electricity can affect our everyday lives! For all who are interested, our lesson plans for this week are posted online at:
Cheers and welcome to our blog!