It happens on a regular basis

Only thing I worry about with toys is if the plastic they use is non-toxic. Most cheap toys sold online aren’t tested for plastic toxicity.

Open pit is much more common for this type of equipment and it’s basically a reverse mountain. Still might be enough regenerative braking from just the weight of the truck though.

Kahn academy. It’s free and goes as deep as you want. I had to brush up on some stuff and it was great.