New answers tagged

0

I will give contra example for some of the comments: You can blow with mouth wide open very hard and then the speed of air is high but it is still worm. Also you can blow with lips pursed very gently and the air speed is slow, but still you feel it is colder … so the right answer is : air comes out cold, because it expands coming out of small opening.


0

(NASA lost a Mars Probe) What you can do: There is a well-known $pV=\frac{m}{M}RT$ universal gas formula. Here: $p$ is the pressure $V$ is the volume $m$ is the mass $M$ is the molar mass of the gas $R$ is the universal gas constant ($8.314$) $T$ is the absolute temperature (in Kelvin) Although your question literally interpreted asks for the weight of ...


0

I believe all these answers miss a practical detail - and that we have to be careful about how we use absolute and gage pressures too. At depth the tire would probably collapse under the squeeze of the increasing external water pressure and the bead would probably pop off the rim and all the air inside would probably escape before it reached that depth. ...


1

I think this happens because when windows are open then there is free airflow in the room and doesn't affect the shutting of the door but when the windows are closed then there is obstruction in airflow. The pressure of air inside the room become less than the pressure of air outside the room and hence obstruct the shutting of the door in the room having all ...


1

I think the sound makes the particles move more because there's more interaction when the sound particles are included, but I'm probably wrong because I don't know much about physics...


0

The percentage by which the pressure lowers on the leeward side of your finger is minuscule, so it barely affects the rate of evaporation.


2

I think the answer in this reddit discussion is basically right. But first, I should point out that pure diffusion is excidingly slow. A quick calculation shows that it would take 500 years for an average water molecule to diffuse 1 meter. Of course, in most cases real particles diffuse much faster thanks to small turbulent flows. This already hints at one ...


0

@Flojo1 - I know more about RF atmospheric refraction than optical, so this won't give you anywhere near a complete answer. But I can say a few things that may be of some use. First, looming is no more than enough vertical refraction in the earth atmosphere that an object on the surface looks like it is above the surface. Sinking is the opposite. There's ...


2

He is referring to the second paragraph of 31-3: However, we shall discuss the formula we have obtained, in various possible circumstances. First of all, for most ordinary gases (for instance, for air, most colorless gases, hydrogen, helium, and so on) the natural frequencies of the electron oscillators correspond to ultraviolet light. These ...


3

First, the reason why the finger becomes more wind-sensitive with some saliva isn't that the saliva evaporates but because the saliva, or water, is a good thermal conductor. The finger has to be warmer than the air so the heat flows from the finger to the air and a good thermal conductor such as saliva helps this flux to take place. Second, because it's the ...


0

I think some cargo holders generally aren't concerned about maintaining pressure, most things survive, it's only when pets and people are involved that pressure becomes an important aspect. If the air pads (I guess you're talking about large bubble wrap) were filled with enough air to be tense on the ground the reduced air pressure at 10,000ft would have a ...


2

In an open box, it depends on how high the bee flies. In aviation, this is called the ground effect - if you're flying low enough, you have extra lift, because you're not only pushing against the air, you're pushing against the ground (the air flow below you dissipates and spreads out before reaching ground, if you're high, but not if you're low). A typical ...


1

Even if you call the term dynamic pressure, and has units of pressure, it is not a pressure at all. It is a necessary contribution to the total static pressure, though, And it is the static pressure that matters when you move a piston in a gas. The static pressure is also related thermodynamically to the temperature, in the first case as the average ...


3

the bee makes movement of air that causes air pressure, and this pressure is distributed around, if the box is closed, the amount of lift above because low pressure is equal to the weight below caused by air pressure, so no change on weight but if the box is open, i think that the air outside the box will flow in and the air below will 'hit' the box, ...


3

This is really three separate questions. Static and dynamic pressure: It is the static pressure that really matters in practical situations. The dynamic pressure is related to the kinetic energy of the fluid which, when it changes, causes a corresponding change in the static pressure. Condenser/evaporator application: The basic Bernoulli equation ...


0

Imagine throwing a steel ball and a ping-pong ball of same size really hard. The ping pong ball will fall down quickly, and hit earth long before the steel ball is done climbing; so the steel ball flies longer. Now imagine throwing them rather lightly up, but from a cliff top. The steel ball will quickly turn and fall with high speed, whereas the ping ...



Top 50 recent answers are included