Take an example that there is a bubble in a bottomless container (saying that that is possible) if the bubble is deep enough would the water pressure cancel out the buoyancy acting on the bubble and if so what would happen to the bubble? And at what point would this be (This question is slightly different to the other one as this is not limited to the deepest point on earth)
97638
Can water pressure ever become high enough to trap gas bubbles and/or keep them from surfacing?
60989
Fluid pressure is calculated as  $$\rho = hdg$$  where $\rho$ is fluid pressure, $h$ is depth from surface, $d$ is density of fluid and $g$ is acceleration of gravity.  It used to make sense to me for square or rectangle shaped containers since pressure means force per unit area.  $$Pressure = \frac{Force}{Area} = \frac{Fluid \space Weight}{Container's \space Bottom \space Area}$$  and  $$h \times d \times g= \frac{h\times m \times g}{v} = \frac{h\times m \times g}{h \times s} = \frac{m \times g}{s} = \frac{Fluid \space Weight}{Container's \space Bottom \space Area}$$  where $m$ is mass, $v$ is volume and $s$ is bottom area.  I thought that pressure being dependent on $h$ and not $m$ would be acceptable since $m$ is also dependent on $h$ since fluids can't go higher when they have spaces to their sides.  One big obvious mistake I made was to assume that all containers would be squares or rectangles. So, now I can't wrap my mind around the concept that pressures on tennis balls in the following image are equal.    Why are they equal when the weight (and mass) of fluid above them is obviously different?
16819
I noticed that when I had a helium filled, latex balloon inside of my car, it moved forward in the cabin as I accelerated forward. The faster I accelerated forward, the faster the balloon went from the back of the car to the front of the car. The balloon didn't have a string.  This became a game with my 4 year old as we drove home. We figured out where the balloon would go based on how fast I accelerated, turned corners etc.  I expected that it would act a lot like the water in a cup does, but it was the total opposite it seemed.  What forces caused this behavior?  I assumed it has something to do with the fluid dynamics in the closed cabin, but I can't figure it out.
26321
If a pipe extended from just above the ocean floor to outside the atmosphere, would water be sucked up it by the vacuum beyond the atmosphere? If a hole was made in the pipe, above sea level, how would that affect the flow of water? Would it stop it completely?
20848
Given that the boiling point of a liquid is the temperature at which the vapor pressure is equal to the ambient (surrounding) pressure, what significance does a liquid's vapor pressure have in the formation of bubbles that happens at and above the boiling point?    The definition of boiling point seems to imply that the pressure inside of the bubbles must be at least as great as the liquid's vapor pressure in order to balance the outside pressure, but is there any particular reason why the pressure inside of the bubbles is related to the vapor pressure?    The vapor pressure seems to be a measurement describing the tendency of the molecules to escape from the surface of the liquid, but I don't see how that relates to bubble formation within the liquid.  This question has bothered me for a while, so any help would be much appreciated.
116189
Suppose I put a mug in the water and then tilt it so that the water gets inside. It then floats due to buoyant force. But if I try to pull it out then a lot of force is needed. That's due to suction? What exactly happens at the moment when the force I apply is enough to pull the mug out? And what causes the loud pop sound when that happens?
41112
I am confused.  Some sources say it is possible at least theoretically (  ) and some say it is not true (  )  Is it necessary or not that there exists an amount of water around the ship that weights at least the same as the weight of the ship?
8805
If I take a sponge and place it in a shallow dish of water (i.e. water level is lower than height of sponge), it absorbs water until the sponge is wet, including a portion of the sponge above the water level. In other words, it seems the sponge pulls some water from the bath up into itself, doing work, and the water gains some gravitational potential energy.  Where does the energy required to do this work come from? My suspicion is that the answer involves physical and/or chemical bonds between the water and the sponge, or possibly the change in the surface area to volume ratio of the water.
42851
Newton's third law of motion states that every action has an equal and opposite reaction. That is the reason we do not sink into the earth, because when our weight exerts a force on the earth it also exerts an equal and opposite force on us.  But when we stand on quicksand or on fluids we can sink in. How is this possible? Does it not exert an equal and opposite force on us? Or are Newton's laws different in the case of fluids and substances of low densities?
112323
A thin-walled container of mass $m$ floats vertically at the separation surface of the two liquids of density $ρ_1$ and $ρ_2$  . The whole mass of the container is concentrated in the part of height $h$.  The question is to determine the immersion depth $h'$of the container in the lower liquid if the bottom of the container has a thickness $h$ and an area $S$ and if the container itself is filled with the liquid of density $ρ_1$.    I applied the fundamental principle of the statics on the container  $Balance$ $Sheet$:  The weight of the container ($-mg$)  The buoyancy force applied by the fluid with density $ρ_2$ ($ρ_2gSh$)  The weight of the fluid with density  $ρ_1$  (-$ρ_2gSh'$)  I summed up the forces and set them to zero and find my $h'$  but then  realised that the fluid with density  $ρ_1$  applied also a buoyoncy force on the top of the container , and the fluid with density  $ρ_2$  applied a buoyoncy force on the other fluid.  Where's the problem ?
108716
An upcoming adventure will have the party exploring the depths of the ocean. Breathing underwater shouldn't be an issue for them, as there are both items and rituals to take care of that, however, I was wondering what to do about about pressure, since none of these options mention it. I'll have to split my question into two, since they are closely related.   Is pressure an issue in 4e adventures? Is it mentioned in any of the published material? Has it been ruled anywhere that options that enable water breathing also grant immunity to pressure? Should it be an issue? This is somewhat subjective, but I really am wondering what other people have done. Would it be unresonable to assume that these options grant immunity to pressure? Should the players work to find another solution?
26333
When watching the part where they go down to Miller, I was bothered by the fact that the waves didn't break despite the fact that the water level is ostensibly only knee-deep (roughly, a wave starts to break when the depth of the water is less than the height of the wave). But then, a friend came up with the idea that the waves are not really waves. Given that the gravitational influence of Gargantua on Miller is, well, gargantuan (I'm not apologizing for that joke) the "waves" are actually mountains of water created by Gargantua's gravity. As such, the "waves" don't really move towards the crew; rather, they are stationary (relative to Gargantua), and it is the rotation of Miller that brings the crew towards the "waves". The reason the ocean is so shallow is because a substantial proportion of Miller's water is used up to make up the "waves".  Is this really a plausible idea? What bothers me about this is that, if it is really the planet that is rotating under the "waves", the crew should have experienced a night-day (or day-night) transition between one "wave" and the next.
42584
Suppose from a height $H$, I throw a ball of mass $M$ and radius $R$ with initial velocity $u$ into a pool of depth $x$ having a liquid with density $\rho$ and coefficient of viscosity $\eta$.  Upto what height will the Water Splash?   This may be a silly question! (Source : my brain) Assume every condition to be identical with no air resistance. Feel free to assume any other parameters if needed.  P.S. $\rightarrow$ I've see similar questions but some of them want an exact answer and some are not so direct while some are incomplete questions...  Small Note : We do not have to consider the highest 'single' drop... Just assuming almost every water droplet jumped upto a height $h$. Ideal conditions...  Feel free to assume the liquid as WATER if required!
2227
This comes from a brain teaser but I'm not sure I can solve it:     You are in a rowing boat on a lake. A large heavy rock is also in the boat. You heave the rock overboard. It sinks to the bottom of the lake. What happens to the water level in the lake? Does it rise, fall or stay the same?   I'd say that the water level drops, because when you drop the stone in the lake, the water level rises according to the volume of the stone, BUT the water level decreases by a volume of water weighting the stone's weight, when you take it off the boat.  Is that correct?
62368
A friend of mine has a homework question and we're having some trouble figuring out what physical mechanisms come into play for this.     An underwater swimmer sees a spherical air bubble that appears to have a diameter $d=$ 1.5 cm. What is its actual diameter?   We are having trouble, specifically, thinking of physical mechanisms that would change the apparent sizes of objects when seen underwater. Is it caused by refraction at the curved surface of the bubble?
90547
What what I understand, hydrostatic pressure is the "weight" of the water pushing against objects. But if this is true, why is hydrostatic pressure perpendicular to the surface it acts on instead of always going down?  For example, if you placed a book on a desk, the book's weight would push against the desk, but gravity is pulling it "down". But if you put another book beside this book the first book wouldn't apply any force on it. The weight exerted from the book always goes down.  Similarly, why doesn't hydrostatic pressure always go down? I understand that if you put a plate on the seabed, the weight of the water would push down on it, but if you just had a vertical plate standing on the bed, why would force push it from the sides?  To sum up, why does hydrostatic pressure act perpendicular to the object instead of always down?
55815
For both containers it is true that:  $p_{bottom}=p_{atm}+\rho gh$ and $F_{bottom}=a*p_{bottom} \iff F_{bottom}=a*p_{atm} + a\rho gh$  I do not know how a scale functions, but I guess that the only force it can count is the force by the liquid on the bottom of each container (the only surface that is in touch with the scale is the bottom of the container). Thus, if we measured the mass of these two masses of water (lets assume that the mass of the containers is negligible) it would appear to be the same in each case. Am I right?