physics question
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Bushmaster

Original Poster:

27,590 posts

310 months

Monday 18th August 2008
quotequote all
You are in a canal boat motoring along a canal. The canal passes over an aquaduct. Does the load on the aquaduct's supports increase as the boat passes over?






bite-me

524 posts

258 months

Monday 18th August 2008
quotequote all
is this homework

smile

Bushmaster said:
You are in a canal boat motoring along a canal. The canal passes over an aquaduct. Does the load on the aquaduct's supports increase as the boat passes over?

groucho

12,134 posts

277 months

Monday 18th August 2008
quotequote all
I suppose so.

Fex2005

282 posts

234 months

Monday 18th August 2008
quotequote all
No

Shuvi

889 posts

237 months

Monday 18th August 2008
quotequote all
No, because the boat displaces water. It displaces an amount of water that equals the boats weight. This means the load never changes.

buggalugs

9,292 posts

268 months

Monday 18th August 2008
quotequote all
I asked this question a year or two ago, IIRC the answer is no. HTH thumbup

gazza_3

6,442 posts

239 months

Monday 18th August 2008
quotequote all
No, but the water pressure on the Aquaduck will.

HTH

s2art

18,942 posts

284 months

Monday 18th August 2008
quotequote all
No. (there may be some effects caused by the boats movement)

elster

17,517 posts

241 months

Monday 18th August 2008
quotequote all
buggalugs said:
I asked this question a year or two ago, IIRC the answer is no. HTH thumbup
This really is a popular quaestion.

hugoagogo

23,438 posts

264 months

Monday 18th August 2008
quotequote all
no, but the load increases on those supports (and the rest of the canal) when that boat enters that section of canal (through a lock or whatever)

Fex2005

282 posts

234 months

Monday 18th August 2008
quotequote all
Shuvi said:
No, because the boat displaces water. It displaces an amount of water that equals the boats weight. This means the load never changes.
yes Thats what I thought aswell yes

Edited by Fex2005 on Monday 18th August 17:16

SiH

1,858 posts

278 months

Monday 18th August 2008
quotequote all
The answer is no. Categorically no.

Please god don't let this become the next aeroplane/conveyor belt conundrum!

hugoagogo

23,438 posts

264 months

Monday 18th August 2008
quotequote all
what about the other question:

a boat floating on a section of canal, say 100m between two locks, has 1 tonne of lead ingots on board

the canal boat captain(?) chucks the lead ingots over the side, one at a time

when he's finished, what happens to the level of the boat and to the level of the water?

what if he has a tank containing 1000 litres of water and he pumps this over the side?

Fex2005

282 posts

234 months

Monday 18th August 2008
quotequote all
dibbers006 said:
Where does the Displaced Water go then? confused
It will be displaced at the ends of the viaduct. Same as if it rains, (the viaduct does not fill up and over flow) it is displaced along the viaduct.

The only time I can see the load increasing, is if the boat was lowered into the viaduct (instead of floating along onto it), and even this would only be a temporary load until the water is displaced off the viaduct at each end.


Edited by Fex2005 on Monday 18th August 17:23

Fex2005

282 posts

234 months

Monday 18th August 2008
quotequote all
dibbers006 said:
Where does the Displaced Water go then? confused
It will be displaced at the ends of the viaduct. Same as if it rains, (the viaduct does not fill up and over flow) it is displaced along the viaduct.

The only time I can see the load increasing, is if the boat was lowered into the viaduct (instead of floating along onto it), and even this would only be a temporary load until the water is displaced off the viaduct (at each end into the canal).

Edited by Fex2005 on Monday 18th August 17:25

White-Noise

5,500 posts

279 months

Monday 18th August 2008
quotequote all
I can see why there are lots of no's on here. But if you put loads of boats on the canal then there may be a noticeable rise in the water level. Surely if the water level on the aquaduct is higher then the answer would be yes! So why wouldnt the answer be yes?

DeadMeat_UK

3,058 posts

313 months

Monday 18th August 2008
quotequote all
At least we can categorically say it won't be able to take off.

SLacKer

2,622 posts

238 months

Monday 18th August 2008
quotequote all
hugoagogo said:
what about the other question:

a boat floating on a section of canal, say 100m between two locks, has 1 tonne of lead ingots on board

the canal boat captain(?) chucks the lead ingots over the side, one at a time

when he's finished, what happens to the level of the boat and to the level of the water?

what if he has a tank containing 1000 litres of water and he pumps this over the side?
Wouldn't he be better off selling the lead....it is fetching a good price.

groucho

12,134 posts

277 months

Monday 18th August 2008
quotequote all
Shuvi said:
No, because the boat displaces water. It displaces an amount of water that equals the boats weight. This means the load never changes.
If the water went over the side I'd agree with you. biggrin

groucho

12,134 posts

277 months

Monday 18th August 2008
quotequote all
SiH said:
The answer is no. Categorically no.

Please god don't let this become the next aeroplane/conveyor belt conundrum!
What was that one, then?