Why does water whirl when flushed and why does tomato juice form rings on a glass?

[Joonasja]

Hi everyone!
I have two rather simple, everyday phenomenons that I can't explain.
1) Why does water whirl when you flush it down, why doesn't it go in a straight line?
2) When you're drinking tomato juice, then why are there rings on the glass (after every zip there remains some juice on the glass, but why isn't it "even" in every place but forms rings.)?

You don't actually have to write any complex math here, just a definite answer so that an high school student can understand it.

 

[AC130Nav]

Hi everyone!
I have two rather simple, everyday phenomenons that I can't explain.
1) Why does water whirl when you flush it down, why doesn't it go in a straight line?
2) When you're drinking tomato juice, then why are there rings on the glass (after every zip there remains some juice on the glass, but why isn't it "even" in every place but forms rings.)?

Homework Statement

Homework Equations

The Attempt at a Solution

You don't actually have to write any complex math here, just a definite answer so that an high school student can understand it.

First takes:

1. The "old wives' tale" that it is because of coriolus is wrong. That only works on the large scale. The jets are directed to cause a swirl to help clean the bowl.

2. The rings form when the glass is stabilized long enough for the layer of surface tension to leave deposits.