Quiz

[Neil WyattModerator @neilwyatt]

Two 2000-ton ships set off from the Azores. One heads east, one heads west.

All other things being equal which ship needs the most fuel to make 20 knots?

Neil

[Neil WyattModerator @neilwyatt]

[TobaccoBurnerParticipant @tobaccoburner]

Relative to what?

[JasonBModerator @jasonb]

Which way is the wind blowing and how strong and whats the tide direction and strength. and if one is a sail boat……

Edited By JasonB on 09/02/2015 15:01:50

[FMESParticipant @fmes]

Well, if all other things are being equal they'll both use the same amount.

[JasonBModerator @jasonb]

But if they both had equal weather conditions say a 10knot North Easterly wind. One could take advantage but the other would be disadvantaged.

[FMESParticipant @fmes]

Wouldn't be 'equal' then Jason

[Ady1Participant @ady1]

All other things being equal

The one heading east

which ship needs the most fuel to make 20 knots

oops edit, the one heading west

Edited By Ady1 on 09/02/2015 15:27:30

Edited By Ady1 on 09/02/2015 15:28:37

[Nick_GParticipant @nick_g]

.

Are we talking about knots of speed here.?

nick

[Roger Provins 2Participant @rogerprovins2]

The one that is going in the same direction as the rotation of the earth?

[JasonBModerator @jasonb]

Isn't that the catch.

Is both having a North easterly equal

Or is both having a head wind equal

Anyway bring on question No 2

Two parting tools, one mounted at the front, one at the back…………all being equal……………which cuts better

[Ady1Participant @ady1]

Posted by Roger Provins 2 on 09/02/2015 15:30:58:

The one that is going in the same direction as the rotation of the earth?

That's my guess, then edited for the MOST fuel, ie going against gravity and rotation, so west

[john kennedy 1Participant @johnkennedy1]

Neither, they are both under sail ?

[Roger Provins 2Participant @rogerprovins2]

Posted by JasonB on 09/02/2015 15:32:52:

Isn't that the catch.

Is both having a North easterly equal

Or is both having a head wind equal

 

Anyway bring on question No 2

Two parting tools, one mounted at the front, one at the back…………all being equal……………which cuts better

The one pointing forwards cuts the metal better BUT the one pointing backwards cuts YOU better.

Edited By Roger Provins 2 on 09/02/2015 15:39:57

[FMESParticipant @fmes]

Time flies like an arrow

Fruit flies like a banana

[Neil WyattModerator @neilwyatt]

Ady gets the point!

Neil

[BikepeteParticipant @bikepete]

Looks like the prominent scientist was Yakov Perelman and the original statement of the problem is possibly here (with maths!).

Edited By Bikepete on 09/02/2015 16:05:39

[Speedy Builder5Participant @speedybuilder5]

Coriolis effect ??

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

[John Stevenson 1Participant @johnstevenson1]

downhill ?

[jason udallParticipant @jasonudall57142]

All the above not withstanding the surface speed of a ” stationary” object …due to 1 rev/24hrs….
Lets see… equitorial circ…24, 900 miles
So for rock and roll about 1000 mph…
Thus the ship travelling east is doing 1020 and west would bound 980mph.

Now just try explaining that to gatso

Edited By jason udall on 09/02/2015 17:44:54

Edited By jason udall on 09/02/2015 17:46:02

[Nick_GParticipant @nick_g]

.

Slightly off topic I know but in some ways not.

The salinity of the water effects the ships draft. Thus if for some reason the salinity on one direction was higher the ship would not sit as deeply in the water so the hull would have less resistance.

Trivial point you might think. But a friend of mine was a navigator and if their destination was a port in a fresh water estuary for example they would have to work out how much deeper they would sit in the water if that ports water depth was marginal for them. Of course factored in would have to be the loss in weight of several thousand tons of fuel they had used on the passage.

So actually a real world issue.

Nick

[Neil WyattModerator @neilwyatt]

Plimsoll lines.

Marked off with things like 'winter north Atlantic' to account for temperature and seasonality. Others are summer, tropical, fresh and tropical fresh (I think).

Neil

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Neil Wyatt on 09/02/2015 19:02:33:

Plimsoll lines.

Marked off with things like 'winter north Atlantic' to account for temperature and seasonality. Others are summer, tropical, fresh and tropical fresh (I think).

Neil

.

Mmm … ?

Given that the original Plimsoll Line was One Inch … I wonder what difference the reduction to 25mm made to the load-capacity of the World's shipping.

MichaelG.

.

P.S. … don't remind me about centre-lines … those interested in profit will always work tolerances to their favour.

[Diane CarneyModerator @dianecarney30678]

Posted by Neil Wyatt on 09/02/2015 15:52:09:

Centriufugal force – a force referred to by second rate mathematicians and third rate physicists. There is no such thing. One can only have a lack of centripetal force.

Diane

Edited By Diane Carney on 09/02/2015 21:26:16

[Mark CParticipant @markc]

Depends on your point of view!

Mark

ps. Or terms of reference

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