# Tag Info

### Do solids also have a vapour pressure?

I have some different approaches to understand it If we know how to find vapour pressure of solid, we get the answer of this question. We take a sealed container in which a piece of ice is taken. We ...
1 vote
Accepted

### Understanding Pressure Transmission and Lift Mechanics in a Hydraulic Lift

First: pressure in fluids an gases is the same in all direction, so your "downward pressure does not exist. Say the thin tube is left, so you have a downward force F1 on the left piston, this ...
• 6,366

### Why is pressure in the outermost layer of a star lower than at its center?

Imagine you are sandwiched between two moon like objects each with mass M. The forces acting on you is $$F_{centre} = \frac{2 \times G\times M\times M}{D^2}$$ where D is the distance from the centre ...
• 5,677

### Proportionality of Pressure and Temperature in defining Absolute Temperature scale

In defining the ideal gas temperature scale, it is assumed that the pressure of the gas at constant volume is proportional to the temperature $T$. How can we verify whether this is true or not? Are we ...

### Why is pressure in the outermost layer of a star lower than at its center?

Considering the only force keeping the star together is gravitational in nature, Gravity is also what's keeping our oceans stuck to the Earth's surface. Where's the pressure at its highest, near sea ...
• 890

### Why is pressure in the outermost layer of a star lower than at its center?

I believe you are confusing "force of gravity" with "pressure." The gravitational pull (or local acceleration $g$) is indeed zero at the center of the Sun, and a maximum elsewhere ...
• 9,463

### Why is pressure in the outermost layer of a star lower than at its center?

Perhaps the confusion in the question arises because you are thinking of a rigid spherical shell of constant density, and you know that inside such a shell the gravitational field is zero? A ball of ...
• 79

### Why is pressure in the outermost layer of a star lower than at its center?

This is an exercise in hydrostatics. Imagine the sun consisting of a sphere of water. The deeper you go beneath the surface, the more water weight you have bearing down on you from above, and the ...
• 95.3k
Accepted

### Why is pressure in the outermost layer of a star lower than at its center?

There is a lot of mass above the centre, pushing down on it. On the surface there is no mass above. Hence you get high pressure at the centre and zero at the surface.
• 32.9k

### Why doesn't a hydraulic lever violate conservation of energy?

But like using the kinematics formula we get equal displacement. Like we know that mass of the lever increases proportionately with Area so F1/m1 = F2/m2 Now, S = ut + 1/2at^2 S = 1/2at^2 S1 = 1/2F1/...

### Is there any formula for calculating the temperature required for nuclear fusion for a specific pressure?

I would be really thankful if someone could derive/lead me to the formula. There is none, at least no general solution. First off though, we need to know what you mean by "temperature required ...
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### Why does bringing a helium filled latex balloon close to my ear make it feel pressurized?

I've wondered the same and came across an explanation that the helium may act as a lens & cause the sound waves to diverge. Definitely a noticeable phenomenon, I'm surprised there's no simple ...
1 vote

### Is there any formula for calculating the temperature required for nuclear fusion for a specific pressure?

Key to getting the answer you wish is first knowing what the equation of state is for the fusion reactants. This lets you relate pressure, temperature, and density. Please note that all equations of ...
• 95.3k

### What would happen if the sun became the size of the earth?

The ideal gas law gives a first hint of trouble: if you compress gas by a factor of $(r_{sun}/r_{earth})^3\approx 100^3=10^6$, you should expect the temperature to go up by a factor of a million if ...
• 32.9k
1 vote
Accepted

### Work performed by hydrostatic pressure

With a little less math, the power of a stress distribution $\mathbf{t}_n$ over the boundary of a volume $V$ is $$P(t) = \oint_{\partial V} \mathbf{t}_n \cdot \mathbf{u} \ ,$$ being $\mathbf{u}$ the ...
• 10.5k
Accepted

### Question about Young-Laplace equation proof

The observed physical property of surface tension, as tension acting on bodies in the interface, is that this is due to a set of forces that act on all elements of the body that are on the boundary ...
• 39k

### Work performed by hydrostatic pressure

My intuition is that we are looking at a special case of Stokes' theorem, since we are relating surface integrals to volume changes. To this end, it seems clear enough to me that the differential ...
• 722

### External force in the Navier-Stokes momentum equation

Although the question is old, the answer may still be useful to someone else. In my opinion, the pressure imposed by the piston should be included in the equation, not as boundary conditions, rather ...

### Can we have pressure with zero net force on a 2d plane?

Consider a solid rubber block on a frictionless table top. If two opposing forces of equal magnitude are applied to opposite vertical faces of the block, the will be no net horizontal force on the ...
• 5,677