First question on stackexchange. Hopefully somebody can help me out. I'm struggling to express the following eloquently.
I have a rotating syringe tipped with a needle. rotation speed w, with radius r1 and r2.
Now let us pretend that the needle is blocked, so only r1 matters.
My thinking is, due to inertia the pressure observed at r1 is equal to density x fluid 'height' (in an horizontal sense) x acceleration due to inertia.
I'm struggling to calculate this outward acceleration. I've always been told that centrifugal force doesn't exist. So is inertia equal to the centripetal acceleration? It isn't made entirely clear...
Many thanks in advance, if that is too easy, you could also consider the case where the needle is blocked just at the tip (r2) what would be the pressure there.