[jambutty]

Ah! Yes! The multiple pulleys. That got my brain cell agitated a bit too but I got it right.

I got the electric fan question wrong and I’m damned if I can remember which was the other one.

What I can say is if the text were timed I wouldn’t have done so well. I don’t think quite as fast as I used to.

Air will always try to equalise if two connected containers have a different psi Neil. Whether you consider it pushing the air from high to low or pulling (sucking) the air into the low from the high isn’t really relevant.

When you withdraw blood from a vein does the hypodermic withdraw (suck) the blood out or is the heart pumping it out? You can still withdraw blood from a dead body therefore the blood is sucked out.

Re your analogy of the fireman’s water pump. You can still pump water out of a sealed container where air is prevented from replacing the removed water. It takes more effort but it can still be done. Therefore the water is sucked out.

I think that answer is to agree to differ on this issue but so far with three people opting for sucking against one person opting for pushing, the suckers have it.