Just like gases, water can also exert pressure.?

Question

Just like gases, water can also exert pressure. If there's a structural problem on a submarine, the submarine is likely to be crushed as it descends. Is that true or false?


I took a test and The first time I answered true and it was right. Than I failed the test so I had to take it again that same answer was there so I answered True again but when I answered it true again they told me I got it wrong. I was just wandering if it was true or false

Answer 1

Yes, but for different reasons.

Gas exerts pressure within a vessel because atoms/molecules are flying around & colliding with the vessel walls.

Water exerts pressure (on a submarine, per your example) because the earth's gravity is pushing on it.

Remember, pressure is the force exerted by something per unit area of the surface against which it is pushing (P = F/A).

The key difference between liquids and gasses is the origin of the force. For gasses, it's from collisions with a container. Pressure can be changed by changing the gas temperature or changing the container volume. For liquids, the force is applied externally (like gravity). You can't really change the pressure that water puts on a submarine by changing the water's temperature or volume. Gravity's doing all the work.

In summary, this is sort of a trick question, and I would give you credit either way. Liquid water, in and of itself, cannot exert pressure. There has to be some force acting on it. However, gaseous water (steam) could easily exert a pressure, as long as it's in a suitable container.

Answer 2

It's a dumb way to state the question (not the poster but the test giver). When they say "just like gases" what do they mean? Obviously, liquids and gases exert the pressure of gravity so in that sense they're alike and yes the sub would implode underwater. But liquids are incompressible and so water wouldn't exert pressure in the same way as say air does when you fill up a tire.
It sounds like the person who wrote the test doesn't really understand the subject (or English since it should say: Just like a gas . . .).

Answer 3

The pressure on your submarine becomes greater as it goes deeper, and the amount of pressure is the hydrostatic pressure exerted by the water. So that part is true, -yes, water can and does exert pressure.

Will it implode if there's a "structural fault?" well, it depends on what kind of fault, obviously, but yes, eventually the submarine will implode, whether there's a fault or not, if it goes down beyond its "design limit" depth, because the pressure simply gets greater, and greater, and greater. All subs. are built to a design strength limit, and can (sensibly) go down no further than that.
In your "structural fault" case, the sub's design limit presumably is compromised, and so implosion will occur at a shallower depth than if it were perfect.

So, "Yes" water can exert pressure, and "Yes" you sub will implode.

Answer 4

Absolutely true that water (any fluid) can exert a pressure! Could it destroy a sub? Darn right it can.

Answer 5

Answer: True

Water does exert pressure.

Dr. H

Answer 6

True... the further you descent, the higher the pressure is (literally, the more "weight" of water that's pushing down on you)

Answer 7

Water can exert pressure but it's not compressable.

Answer 8

Most definitely true. Ask any diver. Something went wrong with your second test.

Answer 9

true.