[cupcake2435]

If you anchor 2 boats in a river so they ride in the current parallel and close to each other, they move together as I they were being sucked or pushed? Why?


There is lots of room in a steel ship and it floats easily on the sea, but if you put a holee in the hull it sinks? Why?


When u turn on a faucet to slow it, it is usually rther quiet, but when u increase the flow, it can become quite noisy and even hum loudly. It terms of fluid physics, hat is happening during low and high flow?

Thank you sooo much for helping me with theses questions. :)

[drwls]

<<If you anchor 2 boats in a river so they ride in the current parallel and close to each other, they move together as I they were being sucked or pushed? Why?>>
I assume the boats are not connected to the same anchor. That would be a very bad idea, because they would have to move together and collide as both lines become parallel to the flow.

With separate anchors and with equal line lengths, the water flowing between the boats flows at a slightly faster average speed than on the sides facing the river banks. That has something to do with the nozzle-like constriction formed by the sides of the hulls that are facing each other. This in turn causes a "Bernoulii effect" which tends to push the boats closer together. This force is balanced by opposing sideways components of the lines connecting the boats to their anchors, as the boats move closer together

<<There is lots of room in a steel ship and it floats easily on the sea, but if you put a holee in the hull it sinks? Why?>>

Becasuse the boat fills up with water, of course. This increases the weight of the boat and its contents, and requires it to displace more water to balance the increased weight. It does this by sinking.


<<When u turn on a faucet to slow it, it is usually rther quiet, but when u increase the flow, it can become quite noisy and even hum loudly. It terms of fluid physics, hat is happening during low and high flow? >>
That depends upon your pipe system. It could be the unavoidable onset of turbulence in the faster flowing water, but this should not be very "noisy". The humming could be the result of Van Karman vortex formation at a certain range of water speeds, if there is some sort of obstruction in the flow. This website may be helpful with respect to more complicated causes:
http://www.handymanusa.com/questions...isypipesq.html

[urmod4u]

1) both boats will turn on their anchors downstream - which will probably move them together. Then the Bernoulli laws of fluids will get then closer together.
2) Anything floats if its weight is less than the weight of the water it replaces (Archimedes) when fully immersed. When water replaces the air inside, then the object becomes heavier and it will eventually sink.
3) No noise: laminated fluence.
Noisy: turbulent fluence.
This is a very trivial explication, water fluence is way more complicated. But I guess that this is the answer that your teacher expects.