A question I'm embarrased to ask - earth's spin

xerj writes:

I was talking about Coriolis effect with someone and he asked me about
planes against or with the earth's spin of around 1000mph at the equator.

The Coriolis effect is never a factor for east-west movement along the
Equator.

Additionally, the Coriolis effect due to the Earth's rotation is too
small to have a significant effect on an aircraft.

He asked why this didn't benefit east to west plane travel timewise
and hurt west to east.

The Coriolis effect is not a factor for east-west movement along the
Equator.

Aircraft travelling in the direction of the Earth's rotation weigh
slightly less than aircraft travelling in the opposite direction
because of centrifugal acceleration, but that is unrelated to the
Coriolis effect and is too small to worry about in practice.

--
Transpose mxsmanic and gmail to reach me by e-mail.

"xerj" wrote in message
...
I was talking about Coriolis effect with someone and he asked me about
planes against or with the earth's spin of around 1000mph at the equator.
He asked why this didn't benefit east to west plane travel timewise and
hurt west to east. I couldn't give him a straight answer, and felt like an
idiot when I said "it just doesn't".

What IS the straight answer? The dropping something in a moving vehicle
analogy doesn't work, does it? A plane has a method of acceleration,
whereas a passively dropped object doesn't.

Sometimes really simple questions can give you the worst time.


How about the fact the air the plane is flying through also is traveling
West to East. You are flying into a 1000 mph West to East headwind :-) A
100 mph airplane is flying backwards at 900 mph.

Danny Dot

"xerj" wrote in message
...
I was talking about Coriolis effect with someone and he asked me about
planes against or with the earth's spin of around 1000mph at the equator.
He asked why this didn't benefit east to west plane travel timewise and
hurt west to east. I couldn't give him a straight answer, and felt like an
idiot when I said "it just doesn't".

What IS the straight answer? The dropping something in a moving vehicle
analogy doesn't work, does it? A plane has a method of acceleration,
whereas a passively dropped object doesn't.

Sometimes really simple questions can give you the worst time.

Hi xerj,
I think this is a great question. Back in the [Harumph!] old
days when I learned to fly we were taught in Metorlogy 101 that one indirect
way coriolis force DOES affect east or west airtravel is what it does to the
weather.

The following is quoted from:

TODAY'S TMJ4 WEATHER PLUS; Coriolis force affects wind patterns
Milwaukee Journal Sentinel, The, Sep 18, 2006 by MIKE LAPOINT

"When looking down at the North Pole, Earth spins counterclockwise around
its axis. A point on the equator travels about 1,100 mph, while the points
directly at the poles do not move at all. An apparent force called the
Coriolis force results from this difference in speeds, deflecting objects to
the right in the Northern Hemisphere and to the left in the Southern
Hemisphere. The Coriolis force, combined with solar heating patterns across
Earth, creates distinctive wind patterns that drive weather systems.
One prevailing surface wind pattern that results is in the mid- latitudes,
between 30 and 60 degrees north. Solar heating alone, without Earth's
rotation, would produce prevailing southerly winds. The Coriolis force,
however, deflects these winds to the right, creating prevailing winds out of
the west and southwest known as the westerlies."

So, while coriolis has only a small direct affect, the winds can be a huge
factor in slowing aircraft down on westerly flights. The above is just one
of a bunch of hits from Google about coriolis force and the weather.

xerj wrote:
I was talking about Coriolis effect with someone and he asked me about
planes against or with the earth's spin of around 1000mph at the equator. He
asked why this didn't benefit east to west plane travel timewise and hurt
west to east. I couldn't give him a straight answer, and felt like an idiot
when I said "it just doesn't".

What IS the straight answer? The dropping something in a moving vehicle
analogy doesn't work, does it? A plane has a method of acceleration, whereas
a passively dropped object doesn't.

Sometimes really simple questions can give you the worst time.

Coriolis effect has a very significant effect on planes, just not
directly. Its effect is felt in the wind patterns that is produces in
terms of high and low pressure centers and their rotation. Every time
you fly you account for the coriolis effect by checking the wind
forecasts and doing the wind correction calculations...

Dean

Thanks to all who answered!

"xerj" wrote in message
...
I was talking about Coriolis effect with someone and he asked me about
planes against or with the earth's spin of around 1000mph at the equator.
He asked why this didn't benefit east to west plane travel timewise and
hurt west to east. I couldn't give him a straight answer, and felt like an
idiot when I said "it just doesn't".

What IS the straight answer? The dropping something in a moving vehicle
analogy doesn't work, does it? A plane has a method of acceleration,
whereas a passively dropped object doesn't.

Sometimes really simple questions can give you the worst time.