John Travoltage: Static Electricity & Sparks
Rub John's foot on the carpet, collect charge, and bring his finger close to the doorknob to make a spark.
Drag John's foot back and forth on the carpet to rub electrons onto his body, then drag his hand towards the doorknob. When the gap is small enough for the voltage, a spark jumps! Change the carpet, the humidity and the target to see what makes static shocks bigger or smaller.
About the John Travoltage: Static Electricity & Sparks
Free john travoltage: static electricity & sparks. Rub John's foot on the carpet, collect charge, and bring his finger close to the doorknob to make a spark. Drag, change the sliders and see the result live. No sign-up, works on phone and computer. Built for physics, the john travoltage: static electricity & sparks runs instantly in your browser: change a setting or drag an object and the result updates at once, so you learn by trying things out rather than only reading about them.
Rub John's foot on the carpet, collect charge, and bring his finger close to the doorknob to make a spark. Use it to explore physics ideas at your own pace, then check what you found against the key ideas further down this page.
How to use the John Travoltage: Static Electricity & Sparks
- Use the controls to change Floor, Humidity of the air, Touch, Show electrons, Field lines, and more. The simulation reacts instantly.
- Pick an option such as Nylon carpet, Wool carpet, Cotton rug, Wood floor to switch modes or load an example.
- Press "Rub automatically", "Touch to discharge", "Reset" to start, reset or change what is happening.
- Where you see a glowing handle, object, weight or atom, drag it with your mouse or finger. Everything responds in real time.
- Watch the readouts and graphs update as you experiment, and compare what you see with the key ideas below.
Things to try
- Rub the foot and watch the hair rise.
- Get a spark from far away with lots of charge.
- Raise the humidity and try again.
Key ideas you can learn
- Rubbing transfers electrons and builds up static charge.
- Like charges repel: John's hair stands up.
- A spark jumps when the charge is large enough to cross the air gap.
- Humid air lets charge leak away.
Where this is used in the real world
Static control matters in electronics factories, fuel tankers, hospitals and printers.
Who is this simulation for?
Physics students in middle school, high school and first-year university, teachers who want a quick demonstration for the projector, and anyone revising for exams. It works well for flipped classrooms because students can explore before the lesson.
For teachers: project it on the board, let students predict what will happen, then run it together. For students: change one thing at a time and write down what changes.
Frequently asked questions
Why do you get a shock from a doorknob?
Charge built up on you jumps to the metal knob when you are close enough.
Why is static worse in winter?
Dry air is a poor conductor, so charge cannot leak away.
Is the John Travoltage: Static Electricity & Sparks free to use?
Yes. It is completely free, with no signup, no download and no ads inside the simulation. It runs in your web browser.
Does the John Travoltage: Static Electricity & Sparks work on a phone or tablet?
Yes. It uses touch as well as the mouse, so you can drag objects with your finger. A larger screen makes the controls easier to see.