Easy Aviation question...that I cannot answer!!!

[muckmaw]

Need some help here.

If a plane flies from Los Angeles to NYC, it obviously must fly West to East.

If the planes top speed is 500MPH, but the earth below it is spinning at 1000 mph, how the hell does the plane ever get to NYC?

WOuld'nt it's ground speed by -500 mph?

Does the atmosphere rotate at the same rate as the earth?

[ra]

Yes.

[BlckMgk]

If the atmosphere didn't we'd have some wicked winds, trees would be bent on their sides and we'd be cave dwellers.

Well sorta

The atmosphere is in the "Gas" State... Gas still has density and mass, so anything that has mass can be acted upon by forces. So we move through air as fish move through water..

..... i think..

[muckmaw]

So then flying in the atmosphere could be equated to swimming in the ocean, really.

[muckmaw]

Originally posted by BlckMgk
If the atmosphere didn't we'd have some wicked winds, trees would be bent on their sides and we'd be cave dwellers.

Well sorta

The atmosphere is in the "Gas" State... Gas still has density and mass, so anything that has mass can be acted upon by forces. So we move through air as fish move through water..

..... i think..

Isnt it funny how if you stop and think about something we all take for granted, we realize how complicated it really is?

[Rude]

Originally posted by muckmaw
Isnt it funny how if you stop and think about something we all take for granted, we realize how complicated it really is?

Kinda like when you guys think of me, huh?

[DmdNexus]

Originally posted by muckmaw
Need some help here.

If a plane flies from Los Angeles to NYC, it obviously must fly West to East.

If the planes top speed is 500MPH, but the earth below it is spinning at 1000 mph, how the hell does the plane ever get to NYC?

WOuld'nt it's ground speed by -500 mph?

Does the atmosphere rotate at the same rate as the earth?

It's relativity thing man...

A train passes a station traveling east.

An observer at the station observse the train traveling N mph relative to his position.

A conductor on the train walks eastwarding at M mph...

An observer measures the conductors speed as N+M mph...

Add another train traveling west, a mirror,  a flash light, a few party hats, naked women, psychotic drugs  and you have the theory of relativity...

[MRPLUTO]

The Earth is spinning/moving from west to east (left to right on a map) at 1,000 mph at the equator, 500 mph at 45 degrees north or south latitude, and 0 mph at the poles.

The plane still has this rotational speed, even after it takes off.

In the same way, a space ship still has the rotational speed of the earth as it takes off.  That's why it saves fuel to launch rockets into earth orbit from near the equator:  they get the maximum (1,000 mph) head start on achieving orbital velocity, about 17,500 mph, I think.

The atmosphere rotates with the earth, more or less.  But any air mass moving towards the equator has LESS eastward velocity, and therefore moves west in relation to the surface.  Air masses moving away from the equator have MORE eastward velocity than the atmosphere further from the equator, so it moves east.  This is called the Coriolis effect.  It explains why hurricanes, for example, have the rotation they do.

MRPLUTO

[AKIron]

Well, if you want to figure that plane's absolute speed you need to consider other things as well.

Our earth's speed around the sun: 170,000 kph
Our sun's speed through our galaxy: 70,000 kph
Our galaxy's rotational speed: 790,000 kph
Our galaxy's speed through our universe: who knows?

Jane, stop this crazy thing!

[ravells]

Here is one which puzzled me:

Why is easier to keep your balance on a bycicle when you're moving than when you are staying still?

Ravs

[Sandman]

Originally posted by ravells
Here is one which puzzled me:

Why is easier to keep your balance on a bycicle when you're moving than when you are staying still?

Ravs

Gyro.

[ravells]

Can you give more detail please Sandman? I am not a scientist.

Thanks

Ravs

[Sandman]

Originally posted by ravells
Can you give more detail please Sandman? I am not a scientist.

Thanks

Ravs

I'm not either... I was wrong.

What keeps a bike upright?
This is a classic trick question, as many people with some high school or college physics assume that it is the gyroscopic effect of the wheels that keeps a bike upright. But this is not the reason, and experiments with bikes that have counter-rotating wheels have demonstrated so. The reason a bike stays upright is largely two-fold: rider balance and "steering trail." Rider balance is simple enough to understand, but steering trail requires some explanation. Steering trail refers to the effect produced by the design and geometry of the front part of a bike whereby it tends to slightly correct itself when the front wheel is turned askew from the direction the bike is going. You can see this effect by holding a bike from its seat, pointing the bike north but pointing the front wheel slightly to the left or right and then pushing the bike forward. Notice how the front wheel adjusts itself towards the direction of bike motion. As for the gyroscopic effect of the wheels, only at very high speeds with heavy wheels do they begin to have any significant effect. A simple way to see how little effect gyroscopics have on bike balance is to prop your bike on a curb with the rear wheel off the ground while spinning as fast as you can get it. Then push the bike over. Notice that it falls over just as easily as when the wheel is still.

[ravells]

Very interesting.

Thanks!



Ravs

[DmdNexus]

Originally posted by ravells
Can you give more detail please Sandman? I am not a scientist.

Thanks

Ravs

gyro scopic force... instantious rotation around an axis....

the same force that keeps a top from falling over when it spins.

The force applied to make the wheel spin must be over come to rotate the axis.... so the faster the whell turns... the more force required to change the tilt of the axis.

F=MA.... force = mass times acceleration...

the mass of the rim of the wheel is going around the axis... the faster it goes... the greater the force it has... in order to tilt the axis... the rim also has to move... because it's held into place around the axis by the spokes... well since the rim as has an inertia F=MA going in one direction and constantly changing it's acceleration (instantious rotation around an axis)...a greater force must be applied to the axis inorder to change it's tilt... this same force is applied to the inertia of the rim... blah blah blah blah blah...

confused?... so am I.... don't ask me to explain physics... just look up the odd answer in the back of the book... disregard friction... and the numbers don't have to be precise.... fudge it.