On the back seat of a car lies a spirit level. When the car goes round a sharp bend which way will the bubble in the level move, in towards the curve or out towards the middle of the road?

The liquid in the spirit level, being heavier than the air bubble, will be forced toward the outside of the curve. The bubble will move to the inside of the curve, because it has to move out of the way of the heavier fluid. So-called "centrifugal" force would do the same thing if you tied the spirit level to a string and whirled it around in a circle.

due to Inertia the ball would like to retain its original position

and

be opposite to the direction of the curve,
or,
as you put it, "out towards the middle of the road"

Pin~Jinx /anarchist

quote:

---

Originally posted by Pin~Jinx:
due to _ Inertia_ the ball would like to retain its original position

and

be opposite to the direction of the curve,
or,
as you put it, "out towards the middle of the road"

http://216.40.241.68/otn/funny/bcyclop.gif Pin~Jinx /anarchist

---

Where did this
ball come from??. The only spirit level I'm familiar with has an air bubble in a liquid ?

In fact, the spirit level gets its name from its liquid: alcohol. Alcohol, if one remembers, is sometimes called "spirits." It is used because of its low freezing point. Ethyl alcohol freezes at -178⁰F.

Just a bit of trivia to stick in your shoe.

Thnx FrankVan,

I meant BUBBLE not Ball.

This question and its answers amount to a rather confused mess. Let's start over. Assume the car is in a country where one drives on the right side of the road. A bottle or tube of water or alcohol, almost filled, but containing an air bubble lies on the floor. When the car makes a right turn the liquid flows toward the middle of the road and the air bubble is at the right. When the car makes a left turn, the liquid flows toward the curb side of the road - the inside of the curve, and the air bubble is on the left or toward the middle of the road. I mention this because very often a lot of confusion arises because we fail to phrase the question clearly. or we answer the question assuming facts not in evidence, such as are we in Europe, The U.K, The U.S? etc.

theoretically i agreed with frankvan, but being an experimentalist at heart i decided to try it out. I took a level in my hand and moved it in an arc. As expected (see frankvan's explanation), the bubble moved towards the direction the level turned in (i.e. a in a car turning left the bubble would move to the left and in a car turning right the bubble would move to the right).