Disclaimer: This is a practice test used to help us study, not an actual exam.

Hi all. I've been building a set of free browser-based physics labs that use race cars as the hook, and I'd really value honest feedback before I take it further.

The idea: instead of reading about friction or energy transfer, you change something and watch the car respond, then read the explanation at the level that suits you.

What's there so far:

• A 3D wind tunnel: change the wings and ride height and watch the airflow, pressure and downforce update live.
• Tyre grip: find the fastest speed through a corner; a friction circle shows when the tyres give up.
• Suspension: springs and dampers over kerbs and potholes; comfort vs keeping the tyre on the road, plus resonance.
• Hybrid energy: harvest energy under braking and decide where to spend it around a lap.
• Pit strategy: tyre wear, pit stops and safety cars vs a rival, then compare with the optimal plan.

Every topic has Basic / School / Advanced explanations, challenges, and printable worksheets. Teachers can make a class code to see which challenges students complete, using nicknames only and no accounts. It works on phones and offline.

It's free with no sign-up and no ads. I made it, so this is my project. Link: https://augmenta.co.za/labs

What I'd love to know:

1. Is anything confusing or wrong (physics included)?
2. Teachers: would you actually use this in a lesson? What's missing?
3. Which lab would you want next?

Thanks for any feedback. Brutal is fine.

The man who d*ed on Goliath today, question - in the pictures it appears he is moving forward with the train, moving the same direction. The train is on a downhill, creating a "floating" effect, explaining how he slipped out of the seat, but I don't understand how he is moving forward with the train. Wouldn't he roll off the back and the train keep moving forward? Maybe the train is decelerating on the downhill, but if this is the case I don't understand how he "bounced" off the train multiple times. Someone please help, and RIP to the poor man and condolences to his family.

Here is a link to a library of free educational simulations across a wide range of interesting or challenging concepts across the natural world. More are coming soon. I'd appreciate your feedback if you have a few minutes to explore (feedback link embedded in each sim). Enjoy.

GlidepathScience.org

Why does the steradian (sr) appear in the denominator if irradiance is the ratio of radiant flux to the receiving surface (which is two-dimensional)?