Dave Doe wrote:
Q2. I have a prop and I drag it through grease - as I do so it turns
to "allow" it it's passage through the grease. Now if I was to hold
the shaft so the prop does *not* rotate - surely that would be harder
to pull through the grease now. ?

Sounds like a slick idea, but I think you'd have to deep fry an awful lot
of french fries before you'd have enough to perform the experiment over a
reasonable distance. That assumes you don't die from a coronary first, what
with having to dispose of all that greasy food first....