And magnetic force is a function of current, and magnetic force is what drives wheels. Technically you are correct, but thick cables are actually needed to do lots of translation from electricity to movement.
For the torque, you can use a low current using more windings, which has the same effect of having a higher current with less windings.
The acceleration you can reach is mostly limited by the peak current and the force constant, but the maximum speed you can reach at that acceleration is mostly limited by the voltage you have available because of the back-EMF. A simplified formula is that the voltage you need is R * I + v * BEMF. The higher the voltage is, the better the insulation between the windings needs to be. You need to find a balance between the different properties.
I don't think there's a problem with cable weight with electric motors. Production EV's today have ridiculous amounts of torque and don't require prohibitively heavy cables.
The issue with acceleration using wheels is gravity. You are limited to 1g, the downforce on the wheels, which you use for traction to push the vehicle forward. Spoilers increase the downforce on the vehicle beyond 1g, but the energy required to do that is proportional to the drag on the spoiler.
Short of a rocket engine, the way to accelerate beyond 1g with a wheeled vehicle is to have a downforce fan. That can be powered by combustion or by electricity. I don't know which would offer the highest power to weight ratio.
> Short of a rocket engine, the way to accelerate beyond 1g with a wheeled vehicle is to have a downforce fan.
This electric vehicle is accelerating to 100kph (~28 m/s) in less than 1.5 seconds, which is an average acceleration of about 2g, if I am not mistaken.
Looking around, I have seen 4.0 given as a representative friction coefficient for drag racing tires, which would imply a corresponding peak acceleration of 4g without aerodynamic assistance (again, if I am not mistaken.)
If we are already what-if-ing with wired power delivery, just skip the pantograph and look at what wire-guided missiles do: they have their data lines on a spool, unrolling as they go. For power you certainly wasn't thicker wires, and while you're at it, you'll certainly power the unrolling of the spool instead of just dragging it to spin up. Then if the spool unrolling is for some reason faster than the wheels, the wire will serve as reaction mass, pushing the vehicle. Now we have what's essentially a copper rocket that isn't constrained by downforce and tire grip at all.
I’m not sure having a ‘reverse
Helicopter’ on the back of your vehicle really qualifies as ‘ground vehicle’ at that point. Especially if it’s providing enough force to literally drive upside down on a ceiling somewhere.
