Jerry, very true.
I had to think for a long time to be sure I had it right. Your analogy of the on-car balancing is correct. The wheel that's spinning is indeed spinning at twice the speedo reading.
I've seen people stuck on ice on a flat parking lot where one rear wheel is spinning and they probably have the speedo at 60 MPH.
They'll eventually melt thru the ice and start burning rubber, or possibly snap something in the drivetrain.
The old trick of gently applying the brakes on an open rear end while easing into the throttle to get moving is beyond their capabilities.
