Physics talk

[mossy1200]

Centrifugal force is what they teach you in high school cause your dumb undeveloped teenage brain can't comprehend that the direction of the force is towards the center of rotation.

And it works well for most people. If you want to know more most universities cover it in 100 level physics.

You better hold on tight to the merry-go-round or you might fly into the middle.

[jim.cox]

the concorde strechs two foot longer in full flight

That figure seems more than a little far fetched - can you provide a reference?

[oneofsix]

That figure seems more than a little far fetched - can you provide a reference?

Nice challenge I thought two foot sounded like what I had heard but a quick google and most results are saying 6 - 10 inches.

http://www.britishairways.com/concor...e.htmlConcorde measures 204ft in length - stretching between six and ten inches in-flight due to heating of the airframe.

www.manchesterairport.co.uk › At the AirportConcorde G-BOAC (affectionately known as 'Alpha Charlie') became the second ... During flight Concorde could stretch between 15 and 25 centimetres due to


Perhaps the two foot was the urban myth version.

[pzkpfw]

You better hold on tight to the merry-go-round or you might fly into the middle.

If you let go, you'd fly off (away, at a tangent) in a straight line in the direction you were going. The force, that keeps you going around and around instead of flying off in that straight line, is towards the centre of the merry-go-round. (Similar, in a way, to Earths gravity keeping our Moon in orbit, instead of travelling off somewhere else).

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

http://en.wikipedia.org/wiki/Centrif...e_(fictitious)

http://en.wikipedia.org/wiki/History...ripetal_forces

[HenryDorsetCase]

If you let go, you'd fly off (away, at a tangent) in a straight line in the direction you were going. The force, that keeps you going around and around instead of flying off in that straight line, is towards the centre of the merry-go-round. (Similar, in a way, to Earths gravity keeping our Moon in orbit, instead of travelling off somewhere else).

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

http://en.wikipedia.org/wiki/Centrif...e_(fictitious)

http://en.wikipedia.org/wiki/History...ripetal_forces

thanks for these links. And they say you never learn stuff on KB

[huff3r]

In theory ... GPS measures across the Earths surface ... (the earth being round) so one may assume climbing/descending speeds are not entirely true.

Vehicle GPS tracking systems should be entirely reliant on Global positioning changes to log speed across the earths surface. Not repeating speedometer readings.

That's a pretty poor theory, as then an aircraft with a GPS backed up Inertial Reference Unit would be stuffed. GPS can and does give a 3d fix in space using four satellites, but your best bet is 5 or 6 so you know if ones dodgy. So it'll quite happily give you your velocity in any direction, including straight up or down if your driving on a vertical surface

[Dave-]

You better hold on tight to the merry-go-round or you might fly into the middle.

Honestly don't worry about it, if you've got this far in life without needing to know it you've either been very lucky, or your livelihood hasn't required the knowledge, you'll get through the rest of life not knowing too.

[oneofsix]

Honestly don't worry about it, if you've got this far in life without needing to know it you've either been very lucky, or your livelihood hasn't required the knowledge, you'll get through the rest of life not knowing too.

wonder if this guy cared in it was Centrifugal or Centripetal, guess he was just glad it worked.

http://www.youtube.com/watch?feature...&v=1Igk59dxK2E

[Oakie]

If the curvature of the earth was the only confounding factor, and the radar got him at 62, he would actually be going faster, so ping him for 63.

You could always add the speed of then earth's rotation and do him for about 16062kph (although the 1600kph is at the equator)

[Berries]

You could always add the speed of then earth's rotation and do him for about 16062kph (although the 1600kph is at the equator)

Unless he is going the other way.


Stick that up your doppler.

[mossy1200]

If you let go, you'd fly off (away, at a tangent) in a straight line in the direction you were going. The force, that keeps you going around and around instead of flying off in that straight line, is towards the centre of the merry-go-round. (Similar, in a way, to Earths gravity keeping our Moon in orbit, instead of travelling off somewhere else).

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

http://en.wikipedia.org/wiki/Centrif...e_(fictitious)

http://en.wikipedia.org/wiki/History...ripetal_forces

You crack me up. You link the very information that shows that you dont understand what cetripetal force is.

Gravity from the mass of the Earth and the Moon attract each other.
The centripetal force is what is stopping them from coming together.

The centripetal force is outwards and not in. The balance of the mass and the cetripetal force is what maintains the distance as an orbit.

The other example is the roller coaster. The carts are on the inside of the loop. Your theory would have the cart on the outside being pulled into the centre. Im feeling safer on my roller coaster than yours.


The faster you revolve an object through rotation the higher the outwards G forces that act on the mass in rotation.
The tyre wishes to leave the centre point and expands with the limiting factor being the strength of the construction.
Turn it fast enough the tyre becomes taller and skinnier.

You need to read your link again im afraid.

[Dave-]

You could always add the speed of then earth's rotation and do him for about 16062kph (although the 1600kph is at the equator)

Heisenberg was out driving one day, he was pulled over by a policeman. The policeman asked, "Do you know how fast you were going back there? Heisenberg replied, "No, but I know where I am."

I once thought about dobbing a police officer in for speeding, I was sitting still on my motorcycle and the world was moving past me!....lol

rastuscat have you had either of those excuses yet? can you tell me a bedtime story about some of the excuses you have heard?

[Oakie]

Unless he is going the other way. Stick that up your doppler.

Thought about that too but it just made my head hurt. A fine for going 15937kph backwards?

[Ocean1]

Heisenberg replied, "No, but I know where I am."

Well he would , wouldn't he, just on principle.

[Dave-]

You crack me up. You link the very information that shows that you dont understand what cetripetal force is.

Gravity from the mass of the Earth and the Moon attract each other.
The centripetal force is what is stopping them from coming together.

The centripetal force is outwards and not in. The balance of the mass and the cetripetal force is what maintains the distance as an orbit.

The other example is the roller coaster. The carts are on the inside of the loop. Your theory would have the cart on the outside being pulled into the centre. Im feeling safer on my roller coaster than yours.


The faster you revolve an object through rotation the higher the outwards G forces that act on the mass in rotation.
The tyre wishes to leave the centre point and expands with the limiting factor being the strength of the construction.
Turn it fast enough the tyre becomes taller and skinnier.

You need to read your link again im afraid.

If you have an object revolving through rotation (what? I know right?) and it's not changing speed, is it accelerating?