Who knows

[Notch7]

Yes temporarily due to the wave caused

thats certainly a good point

I guess since a aqueduct is quite narrow with not much space either side a wave will get pushed forward, so the water volume in front of the barge will increase.

 

[ReganAndCarter]

the displaced water went over the top of the bucket,

But you would feck your scales up.

 

[motorbiking]

Except, of course, that the displacement of the barge moves away an equal weight of water, so the answer is no.

"Displacing water locally" raises the water level by a tiny amount over the entire canal. It might be enough to discern by precision measurement close to the vessel, but the boat does not have a footprint of increased pressure under it. Divers are not crushed every time a ship passes above.

Sticking to the exam question its a moving barge in a canal - the canal is quite narrow and the water will rise as the barge passes through. So the answer to the question is Yes. Depending on the speed.

In the open water of course the impact of the ship, over a trillion tonnes of water, will be tiny. We do know that large waves increase the water pressure. The fact that the increase is small, does not change the physics.

 

[motorbiking]

thats certainly a good point

I guess since a aqueduct is quite narrow with not much space either side a wave will get pushed forward, so the water volume in front of the barge will increase.

and to the sides. Google "Froude numbers"

 

[bernardgreen]

Sticking to the exam question its a moving barge in a canal - the canal is quite narrow and the water will rise as the barge passes through. So the answer to the question is Yes. Depending on the speed.

Most viaducts have a footpath built over the water that allows displaced water to flow back past the barge.

Navigable aqueduct - Wikipedia

en.wikipedia.org

 

[Highway Man]

Indeed, you were the first person to correctly identify the vital bit: where the water goes.

Absolute rubbish. I was the only one with any credibility to answer this questiion. Everybody just followed my answers. Muppetts.

 

[Highway Man]

Except, of course, that the displacement of the barge moves away an equal weight of water, so the answer is no.

"Displacing water locally" raises the water level by a tiny amount over the entire canal. It might be enough to discern by precision measurement close to the vessel, but the boat does not have a footprint of increased pressure under it. Divers are not crushed every time a ship passes above.

Exactly what I had said.

 

[motorbiking]

Exactly what I had said.

So based on the Barge moving and the Canal being reasonably snug. Are you a Yes or No to the exam question?

 

[Highway Man]

So based on the Barge moving and the Canal being reasonably snug. Are you a Yes or No to the exam question?

NO would be my answer. I am not a physicist by any means, but based on what I have been taught that is my understanding.

 

[Highway Man]

Sticking to the exam question its a moving barge in a canal - the canal is quite narrow and the water will rise as the barge passes through. So the answer to the question is Yes. Depending on the speed.

In the open water of course the impact of the ship, over a trillion tonnes of water, will be tiny. We do know that large waves increase the water pressure. The fact that the increase is small, does not change the physics.

But pressure does not neccessarily equate to weight? The deeper you go under water the pressure increases but the weight of the water remains static.

 

[motorbiking]

But pressure does not neccessarily equate to weight? The deeper you go under water the pressure increases but the weight of the water remains static.

by volume yes, but the wave is itself additional water. The mass of the water and therefore the pressure at the bottom is based on the the volume of the water above. The deeper you go in the water the less it makes a difference.

https://ocw.mit.edu/courses/2-017j-design-of-electromechanical-robotic-systems-fall-2009/51e6a1ab5a7fa9937bdb7aca645897fd_MIT2_017JF09_ch06.pdf

 

[MNW67]

I want to change my answer from no to somewhat, depending on how quickly the locally displaced water leaves the aqueduct.

 

[motorbiking]

No changes are allowed - First answer is the final answer

 

[noseall]

I'm also wondering whether the stability of the structure is affected if a lot of vessels are stationary on the aqueduct?

 

[motorbiking]

I'm also wondering whether the stability of the structure is affected if a lot of vessels are stationary on the aqueduct?

What do you think?

Spoiler

As long as nobody is craning in lots of additional barges, the answer is No their weight is distributed across the whole system.