Tornadoes and Centripetal Force

[Maggie Kahman]

Dont ask me where I come up with these questions. Your guess is as good as mine.

It was only 10 minutes ago I was snuggled up in bed about to fall asleep, when I thought of it. I was trying to figure this out in my head, but I couldnt and the urge to get up and post a new thread was almost unbearable. I had better ask my question before I forget what it was.

Does centripetal force have any effect on a tornado's funnel? If so, why doesnt this force pull the funnel apart?

 

[David Wolfson]

I'll take this one before bed, myself, Maggie. My physics is limited but enough to answer.

Centripetal force is that force necessary to cause a mass to follow a circular path at constant speed. Think of a ball on a tether. By Newton's First Law, when you impart velocity to mass it wants to keep going in a "straight line" and constant speed. To cause it to depart from the straight line and speed you have to exert force on it. In the case of the atmosphere, air wants to keep going in a straight line unless you force it to do otherwise.

The higher pressure outside the core of a tornado is the centripetal force that pushes in on the air to make it circle. The lower pressure in the core comes from air rising away from the ground and up into the storm. Without the lower pressure in the core the vortex pulls itself apart.