I'm still in a spin over this.?

Question

One thing I had difficulty with in my Physics degree was the Coriolis acceleration, and its related force and effects.
Anyone know of a good book or website which explains this clearly to the LAYPERSON?
Any knowledge you have yourself would also be appreciated.

Answer 1

I'm sorry I can't recommend any texts on the subject. But it all stems from the conservation of angular momentum - similar to Newton's 2nd law, but in a rotating frame of reference.

As angular momentum simplistically is dependant on mass, angular velocity and radius of the mass from the centre of rotation. If the centre of mass is moved towards the centre of rotation (reducing the moment of inertia), then the angular velocity needs to increase in order to conserve the angular momentum. To a rotating observer, this would be seen as an acceleration.

Coriolis is very important to helicopter design, some 1st year texts on helicopter design may help.

Answer 2

No books to recommend but I can put your mind at ease over it.

Imagine you stand 3m away from the north pole. In 24hrs you'd spin in a circle 6m across and only 20m in circumference.

If you stand at the equator, the circle is 12800km across and 45000km circumference. that means that the equator moves faster than the poles. So imagine shooting a shell from a big cannon directly north from the equator where the eastward component of the velocity is over 1000km/h. As the shell moves north, it maintains it's eastward component of velocity but the earth underneath doesn't move east as fast. It makes it look like the shell is going to drift eastward. Over short ranges this can acually be solved rather simply. The eastward drift gets faster as the shell moves further north. Getting faster? That's an acceleration. Accelerations require forces. This is the mythical coriolis force. The north component stays the same and over short distances the horizontal velocity increases roughly proportionally to the distance north.

Hmm. That probably doesn't tell you anything you don't know but maybe ihelps. Hope so

Answer 3

Pretend you are sitting on a seesaw across from someone. But instead of the seesaw moving up and down, it spins. Now you have a ball and throw it toward the other person while you both are spinning. If someone was standing behind you at the place you throw the ball, the ball will look like it moves straight and the other person will have moved before he catches it. But to you it will look like the ball is curving away from the other guy. If you both are spinning counter clockwise, the ball will look as if it curves to the right from your point of view. It will look like it curves to the left from the other person point of view. It will look like it goes straight from the person standing behind you.

Answer 4

I don't know if this is any help but if you want a good demonstration of this effect, stand on one of those children's roundabouts ( we used to call them teapot lids) and while it is spinning lean towards the middle and try to kick the centre post , you will find that your foot goes sideways in a most odd way

Answer 5

This has a good animation

http://en.wikipedia.org/wiki/Coriolis_effect