All Questions
33 questions
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Pressure measurement using piezometer
When calculating pressure of a flowing liquid,we know that peizometers are used whose one end is open to the atmosphere and the other end is connected to the fluid via a small hole at which we want to ...
- 379
1
vote
1
answer
188
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If an object suspended by a string is immersed in a liquid, will its weight contribute to the pressure at the bottom of the container?
We have a metal sphere completely immersed in a liquid of density A by means of a string.
Since the sphere is exerted by the buoyant force due to the liquid the sphere must also exert an equal and ...
- 491
0
votes
2
answers
627
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On hydrostatic pressure and weight
I'm doing some thought experiments about hydrostatic pressure and weighing setups on scales. This really confused me, so I really want to pick your brain about this and get some clarity.
Consider the ...
- 111
0
votes
1
answer
70
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Do different objects with different surface reaction feel the same pressure under a mass?
Let's imagine somehow your hand could change its surface reaction, and becomes as soft as a rubber ball.
Now if we put it on a table (a hard surface) and put an 1kg object on it, do we still feel the ...
- 1
0
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1
answer
98
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How much does the sky weigh? [closed]
How much does the sky weigh?
I don't know how much the sky weighs. Is the sky gravity?
I tried researching, but I can't find scientific information that is proven.
- 19
13
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3
answers
5k
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What impact does air have on our weight?
Although air is light, it is fluid. So it must exert upthrust on people. So does it mean, in fact, we are heavier than our weight? Also, the gravitational acceleration is bigger than its value?
- 421
1
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3
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674
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Does a floating ship increase the pressure on a scuba diver?
In the article Ship Traffic Increases Dramatically, to Oceans' Detriment
, there is a quote (emphasis mine) :
"I was surprised to see that in 20 years, the growth is almost fourfold, or almost ...
- 12.6k
1
vote
1
answer
182
views
Measuring the correct mass or weight of an object in the presence of atmospheric pressure?
I know due to atmospheric pressure the weight of an object increases, but when we take measurements we do not omit the weight of the column of air above it. So, doesn't it affect the accuracy of our ...
- 195
3
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4
answers
2k
views
Pressure inside when a container is closed
Let us suppose that there is a container with its lid open sitting at the bottom of an ocean. The pressure at the bottom of the container will depend on the water column above it assuming only static ...
- 163
0
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2
answers
151
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Does increasing the circumfrence of a wall around a pond increase the pressure against the wall?
I have a wall that forms a circle around a pond. It is 3 bricks high and 10 ft in diameter. It is made of bricks that weight 20 pounds.
...
- 487
1
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1
answer
178
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Why does the liquid column in a capillary tube exert pressure as its weight is already balanced by surface tension?
I read that the meniscus, due to surface tension, exerts an upward pull to the liquid column below it.
The water rises to a height until the weight balances the pull.
Now liquid exerts pressure ...
0
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2
answers
503
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Does pressure acting on a given surface depend on the weight of an object [closed]
I'm thinking something like if I take a box and place a weighing machine and an object inside it...then if i increase the pressure inside that box would i observe any change the weight of the object? ...
- 57
3
votes
1
answer
129
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What is weight at the particle level? How EXACTLY do atoms exert weight on each other?
This is what my intuition says about how the concept of weight works in a solid.
The light brown arrows are the vectors of gravitational force, the light gray parts are the electron clouds around ...
- 71
0
votes
2
answers
1k
views
Measuring pressure or weight from an uneven weight distributed surface
I am new here so I hope I'm posting it at the correct place.
I am having some troubles with some of my force sensors. My case is like this:
I have a body which have a weight. However, the surface is ...
-1
votes
2
answers
288
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Weight of a container of gas and container shape [duplicate]
Consider a cube shaped container with one mole of gas inside.
Acceleration due to gravity would give the difference in force between the top of the container and the bottom to be mg, with net force ...
- 23
1
vote
2
answers
403
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Where does the buoyant force come from?
If I place a cube in water, the force at the top of the cube, $F_1$ will be $Ah\rho_wg$.
Where,
$A =$ cross-sectional area
$h =$ height at the top
$\rho_w =$ density of water
$g$ = acceleration due to ...
- 109
3
votes
3
answers
400
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What Does a Balance Scale Weigh?
This is, I feel sure, a question I'll eventually be embarrassed about having had to ask, but:
Here is a picture of a balance scale. The black rectangle is a vacuum caused by an incredible coincidence ...
- 17k
1
vote
2
answers
184
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weight of a canister of air
Consider four scenarios:
(on a typical weighing scale)
Measure the weight of a canister of air filled at atm pressure
Measure the weight of a compressed canister of air
Measure the weight of a ...
user86425
0
votes
1
answer
1k
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does the weight of a beaker of water increase or decrease when a submerged ping-pong ball is released? [closed]
if a beaker was filled with 200 cc of water and we tethered a ping pong ball to it's floor and that ping pong ball size is 10 cc .
Q1: what will be the weight of the beaker at that time ? (ignore ...
- 55
54
votes
3
answers
25k
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Will helium in the tires of a bike make it lighter?
I know that helium balloons float because it is less dense than air. I'm not expecting my bike to float, although that would be pretty cool. I just wanna know if replacing normal air with helium in ...
- 1,323
0
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2
answers
67
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Finding pressure of an object whose weight is known is standing on a tilted surface
In the following picture, the striped square represents a box that is standing on a surface that is aligned at $\alpha$ degree angle. Box stands on top of point $T$ (that I forgot to mark on paper), $\...
- 134
16
votes
8
answers
3k
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Can a ship float in a (big) bathtub?
I am confused.
Some sources say it is possible at least theoretically ( http://www.wiskit.com/marilyn/battleship.jpeg ) and some say it is not true ( http://blog.knowinghumans.net/2012/09/a-...
- 263
51
votes
6
answers
14k
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Why do gases have weight?
I know that a gas is made of atoms or molecules moving freely in space.
When these particles hit the walls of where they're kept in they cause something called pressure.
But these particles never ...
- 647
5
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4
answers
2k
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Fluid mechanics paradox: The force needed to 'balance' a fluid using a piston
We know that the pressure in a fluid (like water) is dependent on the depth. Consider this example:
For the first setup, solving the pressure at the bottom yields
$P_1 = \rho gh = 1000kg/m^3 \bullet ...
- 862
1
vote
2
answers
209
views
Atmospheric pressure
What is the significance of atmospheric pressure being referenced as 100 kPa ?
Does that really mean 10000 kg/m$^2$ acting upon us ?
If we are measuring only collision force on the surface and not ...
7
votes
3
answers
17k
views
Would a person gain or lose weight after expelling a flatus?
Considering the chemical composition, mass, and pressure range of typical human flatulence, would a person gain or lose weight after passing gas?
- 187
22
votes
18
answers
16k
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Doesn't a box holding a vacuum weigh the same as a box full of air?
This was recently brought up, and I haven't been able to conclude a solid answer.
Let's say we have two identical boxes (A and B...
- 355
0
votes
2
answers
1k
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Possible solutions to the crown problem of Archimedes [closed]
My teacher was talking about the crown problem, possibly solved by Archimedes using skills about density, weight and other properties that he studied. In the original publication, by Vitruvius in a ...
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11
votes
3
answers
4k
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Why does the air pressure at the surface of the earth exactly equal the weight of the entire air column above it
Why does the air pressure at the surface of the earth (resulting from collisions of molecules on the surface of the earth which has to do with the velocity of the particles) exactly equal the weight ...
- 113
1
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1
answer
1k
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Do different density objects in liquids affect net weight [duplicate]
I would test this but I have no tools to test it with.
If I have a beaker of water and weigh it on a measure. Then I stick my fingers in the water (it doesn't over flow) does the weight change or ...
- 307
5
votes
2
answers
6k
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Does the weight of fluid in a conical container act entirely on the base?
Scenario description
Lets assume both containers have a capacity of 300 litres.
One is a vertical tube as shown in pic 1
Other one is more or less a V shaped containers as shown in pic 2
Both are ...
- 105
5
votes
2
answers
6k
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Difference between weight of water and pressure of water
(I didn't even have a basic formal education in physics. I'm learning through the internet out of my own interest, so if there are any silly mistakes, kindly bear with and guide me through.)
...
- 105
1
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2
answers
4k
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Vacuum to hold an object
How can i check and calculate if a certain vacuum pump can hold an object that weights X kg? By "hold" I mean not let that object fall to the floor due to gravity
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