Horsepower is a term that gets thrown around a lot when it comes to cars, both crank horsepower and wheel horsepower. What's actually the difference?

Whoops! To create a wheel and axle mechanism, we need an axle that can help control the motion of the wheel. This axle is fixed to the wheel through the middle, like this.

Got a few thou lying around? Have an enormous rec room you feel like running rails through? Why, then, this ride-on, hand-cranked kid's train and tracks ...