Why doesn't table tennis float on the surface? How do we calculate buoyancy here?How does one calculate the...
What is the difference between "behavior" and "behaviour"?
What is the opposite of 'gravitas'?
What is the best translation for "slot" in the context of multiplayer video games?
Is expanding the research of a group into machine learning as a PhD student risky?
What is the intuitive meaning of having a linear relationship between the logs of two variables?
Can the discrete variable be a negative number?
How do we know the LHC results are robust?
Short story about space worker geeks who zone out by 'listening' to radiation from stars
Did Dumbledore lie to Harry about how long he had James Potter's invisibility cloak when he was examining it? If so, why?
Do the temporary hit points from the Battlerager barbarian's Reckless Abandon stack if I make multiple attacks on my turn?
Energy of the particles in the particle accelerator
Avoiding estate tax by giving multiple gifts
What does "Allow AS in" do in BGP?
Large drywall patch supports
Number of words that can be made using all the letters of the word W, if Os as well as Is are separated is?
How to check is there any negative term in a large list?
Do sorcerers' Subtle Spells require a skill check to be unseen?
Efficient way to transport a Stargate
Why Were Madagascar and New Zealand Discovered So Late?
Lay out the Carpet
Would a high gravity rocky planet be guaranteed to have an atmosphere?
Invade the Pyramid if you Dare
Is a stroke of luck acceptable after a series of unfavorable events?
How long to clear the 'suck zone' of a turbofan after start is initiated?
Why doesn't table tennis float on the surface? How do we calculate buoyancy here?
How does one calculate the force applied on an object by a magnetic field?Ping-pong ball pontoonTerminal velocity of a steel ball in waterPhysics:Buoyant force and scale readingsIn table tennis, is it possible to play a ball in such a way that it does not bounce off the opponents half of the table?What are the physics behind a table tennis ball launcher?Question about buoyancy force affecting mass measurementHow high should be the edge of a billiard table to not allow undesirable pressures on balls when bouncing off?Physics of a table tennis launcherWhy did this table tennis ball rise to the sky?
$begingroup$
Place the beaker full of steel balls and submerge the table tennis ball under the steel balls. The table tennis ball does not float up. Why does it not float up? Do table tennis balls float when the diameter of steel balls is reduced? How to calculate the buoyancy of steel balls?
newtonian-mechanics forces classical-mechanics fluid-dynamics
$endgroup$
add a comment |
$begingroup$
Place the beaker full of steel balls and submerge the table tennis ball under the steel balls. The table tennis ball does not float up. Why does it not float up? Do table tennis balls float when the diameter of steel balls is reduced? How to calculate the buoyancy of steel balls?
newtonian-mechanics forces classical-mechanics fluid-dynamics
$endgroup$
add a comment |
$begingroup$
Place the beaker full of steel balls and submerge the table tennis ball under the steel balls. The table tennis ball does not float up. Why does it not float up? Do table tennis balls float when the diameter of steel balls is reduced? How to calculate the buoyancy of steel balls?
newtonian-mechanics forces classical-mechanics fluid-dynamics
$endgroup$
Place the beaker full of steel balls and submerge the table tennis ball under the steel balls. The table tennis ball does not float up. Why does it not float up? Do table tennis balls float when the diameter of steel balls is reduced? How to calculate the buoyancy of steel balls?
newtonian-mechanics forces classical-mechanics fluid-dynamics
newtonian-mechanics forces classical-mechanics fluid-dynamics
asked 2 hours ago
enbin zhengenbin zheng
345
345
add a comment |
add a comment |
2 Answers
2
active
oldest
votes
$begingroup$
The ball bearings are behaving as a solid because the forces between the steel balls (i.e. friction) are large enough to hold the balls in position relative to each other.
If you apply enough force to a solid you will cause it to fracture or to cause plastic flow. So for example if you attached a string to the ball and pulled upwards with enough force it would cause the steel balls to flow over each other and the table tennis ball would move up. The force required is related to the yield stress of the solid formed by the steel balls.
You can make the steel balls behave as a fluid by making a gas flow through them. This creates a fluidised bed. The gas pushes the steel balls apart so the friction between them is removed, and in this state the steel balls will behave like a fluid and the table tennis ball would float upwards.
Alternatively just shake the beaker. This is equivalent to adding thermal energy i.e. heating the system until it melts. If you shake the beaker you'll find the table tennis ball floats upwards.
$endgroup$
add a comment |
$begingroup$
Well, what if the steel balls were extremely small, say molecular size. In that case, the constraining annulus would look like a polished steel collar, and would likely hold down the ball even if the glass was shattered, underwater, in a swimming pool. . (The van der Waals forces, and metallic bonds, would account for that.)
But this example given, shows discreet balls of intermediate size, and unless they are magnetized, their coupling with the container is what allows restraint of the tennis ball.
If THIS setup was in the bottom of a deeper pool, and the beaker was shattered,
the steel balls would run radially away, and the tennis ball would pop up.
(Note: I answered this as if there was water in the beaker along with the steel balls and tennis ball. But the answer is not changed by my error.)
The term "van der Waals force" is sometimes used loosely for all intermolecular forces.
New contributor
$endgroup$
add a comment |
Your Answer
StackExchange.ifUsing("editor", function () {
return StackExchange.using("mathjaxEditing", function () {
StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix) {
StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["$", "$"], ["\\(","\\)"]]);
});
});
}, "mathjax-editing");
StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "151"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);
StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});
function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: false,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: null,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
noCode: true, onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});
}
});
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fphysics.stackexchange.com%2fquestions%2f469105%2fwhy-doesnt-table-tennis-float-on-the-surface-how-do-we-calculate-buoyancy-here%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
$begingroup$
The ball bearings are behaving as a solid because the forces between the steel balls (i.e. friction) are large enough to hold the balls in position relative to each other.
If you apply enough force to a solid you will cause it to fracture or to cause plastic flow. So for example if you attached a string to the ball and pulled upwards with enough force it would cause the steel balls to flow over each other and the table tennis ball would move up. The force required is related to the yield stress of the solid formed by the steel balls.
You can make the steel balls behave as a fluid by making a gas flow through them. This creates a fluidised bed. The gas pushes the steel balls apart so the friction between them is removed, and in this state the steel balls will behave like a fluid and the table tennis ball would float upwards.
Alternatively just shake the beaker. This is equivalent to adding thermal energy i.e. heating the system until it melts. If you shake the beaker you'll find the table tennis ball floats upwards.
$endgroup$
add a comment |
$begingroup$
The ball bearings are behaving as a solid because the forces between the steel balls (i.e. friction) are large enough to hold the balls in position relative to each other.
If you apply enough force to a solid you will cause it to fracture or to cause plastic flow. So for example if you attached a string to the ball and pulled upwards with enough force it would cause the steel balls to flow over each other and the table tennis ball would move up. The force required is related to the yield stress of the solid formed by the steel balls.
You can make the steel balls behave as a fluid by making a gas flow through them. This creates a fluidised bed. The gas pushes the steel balls apart so the friction between them is removed, and in this state the steel balls will behave like a fluid and the table tennis ball would float upwards.
Alternatively just shake the beaker. This is equivalent to adding thermal energy i.e. heating the system until it melts. If you shake the beaker you'll find the table tennis ball floats upwards.
$endgroup$
add a comment |
$begingroup$
The ball bearings are behaving as a solid because the forces between the steel balls (i.e. friction) are large enough to hold the balls in position relative to each other.
If you apply enough force to a solid you will cause it to fracture or to cause plastic flow. So for example if you attached a string to the ball and pulled upwards with enough force it would cause the steel balls to flow over each other and the table tennis ball would move up. The force required is related to the yield stress of the solid formed by the steel balls.
You can make the steel balls behave as a fluid by making a gas flow through them. This creates a fluidised bed. The gas pushes the steel balls apart so the friction between them is removed, and in this state the steel balls will behave like a fluid and the table tennis ball would float upwards.
Alternatively just shake the beaker. This is equivalent to adding thermal energy i.e. heating the system until it melts. If you shake the beaker you'll find the table tennis ball floats upwards.
$endgroup$
The ball bearings are behaving as a solid because the forces between the steel balls (i.e. friction) are large enough to hold the balls in position relative to each other.
If you apply enough force to a solid you will cause it to fracture or to cause plastic flow. So for example if you attached a string to the ball and pulled upwards with enough force it would cause the steel balls to flow over each other and the table tennis ball would move up. The force required is related to the yield stress of the solid formed by the steel balls.
You can make the steel balls behave as a fluid by making a gas flow through them. This creates a fluidised bed. The gas pushes the steel balls apart so the friction between them is removed, and in this state the steel balls will behave like a fluid and the table tennis ball would float upwards.
Alternatively just shake the beaker. This is equivalent to adding thermal energy i.e. heating the system until it melts. If you shake the beaker you'll find the table tennis ball floats upwards.
edited 1 hour ago
answered 1 hour ago
John RennieJohn Rennie
279k44555801
279k44555801
add a comment |
add a comment |
$begingroup$
Well, what if the steel balls were extremely small, say molecular size. In that case, the constraining annulus would look like a polished steel collar, and would likely hold down the ball even if the glass was shattered, underwater, in a swimming pool. . (The van der Waals forces, and metallic bonds, would account for that.)
But this example given, shows discreet balls of intermediate size, and unless they are magnetized, their coupling with the container is what allows restraint of the tennis ball.
If THIS setup was in the bottom of a deeper pool, and the beaker was shattered,
the steel balls would run radially away, and the tennis ball would pop up.
(Note: I answered this as if there was water in the beaker along with the steel balls and tennis ball. But the answer is not changed by my error.)
The term "van der Waals force" is sometimes used loosely for all intermolecular forces.
New contributor
$endgroup$
add a comment |
$begingroup$
Well, what if the steel balls were extremely small, say molecular size. In that case, the constraining annulus would look like a polished steel collar, and would likely hold down the ball even if the glass was shattered, underwater, in a swimming pool. . (The van der Waals forces, and metallic bonds, would account for that.)
But this example given, shows discreet balls of intermediate size, and unless they are magnetized, their coupling with the container is what allows restraint of the tennis ball.
If THIS setup was in the bottom of a deeper pool, and the beaker was shattered,
the steel balls would run radially away, and the tennis ball would pop up.
(Note: I answered this as if there was water in the beaker along with the steel balls and tennis ball. But the answer is not changed by my error.)
The term "van der Waals force" is sometimes used loosely for all intermolecular forces.
New contributor
$endgroup$
add a comment |
$begingroup$
Well, what if the steel balls were extremely small, say molecular size. In that case, the constraining annulus would look like a polished steel collar, and would likely hold down the ball even if the glass was shattered, underwater, in a swimming pool. . (The van der Waals forces, and metallic bonds, would account for that.)
But this example given, shows discreet balls of intermediate size, and unless they are magnetized, their coupling with the container is what allows restraint of the tennis ball.
If THIS setup was in the bottom of a deeper pool, and the beaker was shattered,
the steel balls would run radially away, and the tennis ball would pop up.
(Note: I answered this as if there was water in the beaker along with the steel balls and tennis ball. But the answer is not changed by my error.)
The term "van der Waals force" is sometimes used loosely for all intermolecular forces.
New contributor
$endgroup$
Well, what if the steel balls were extremely small, say molecular size. In that case, the constraining annulus would look like a polished steel collar, and would likely hold down the ball even if the glass was shattered, underwater, in a swimming pool. . (The van der Waals forces, and metallic bonds, would account for that.)
But this example given, shows discreet balls of intermediate size, and unless they are magnetized, their coupling with the container is what allows restraint of the tennis ball.
If THIS setup was in the bottom of a deeper pool, and the beaker was shattered,
the steel balls would run radially away, and the tennis ball would pop up.
(Note: I answered this as if there was water in the beaker along with the steel balls and tennis ball. But the answer is not changed by my error.)
The term "van der Waals force" is sometimes used loosely for all intermolecular forces.
New contributor
edited 1 hour ago
New contributor
answered 1 hour ago
David NewellDavid Newell
112
112
New contributor
New contributor
add a comment |
add a comment |
Thanks for contributing an answer to Physics Stack Exchange!
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
Use MathJax to format equations. MathJax reference.
To learn more, see our tips on writing great answers.
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fphysics.stackexchange.com%2fquestions%2f469105%2fwhy-doesnt-table-tennis-float-on-the-surface-how-do-we-calculate-buoyancy-here%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown