Questions tagged [inertia]

Inertia is the tendency of a body to oppose changes to its state of motion. DO NOT USE THIS TAG for moment-of-inertia!

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54 views

Does buoyant force become less effective as acceleration increases?

Lets say a balloon with a certain amount of buoyant lift has a 2 kg mass strapped to it (including engines) and accelerates enough that it perceives a positive 2.5 g inertial force (2.5g * weight) ...
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Does potential energy increase inertial mass of system?

For example, we have a ball with mass m lying on the Earth. Then we lift it to a height h. So, now system Earth-ball have potential energy $E_p = mgh$. From Mass–energy equivalence system got $mass = \...
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Does the nucleus have less inertial mass than sum of inertial masses of constitute protons and neutrons?

In nuclear fusion part of nucleons' rest mass goes into radiation energy. Does it mean that inertial mass of result nucleus decreased?
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Does “Quantized Inertia Theory” violate conservation of momentum? [closed]

This recent news article reports that DARPA is doing work with "quantized inertia", despite their claim that it's not widely accepted by physicists: The Defense Advanced Research Projects Agency (...
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What is “Radiation damping stronger than inertia.”

I'm reading a paper on creating gamma rays in a lab and I've come across a phrase I simply don't understand; "Radiation Damping Stronger Than Inertia". As I understand it radiation damping is just ...
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If there were no inertia would perpetual motion be possible? [closed]

Is it not inertia that makes a flywheel resist being put into motion? And if that is true, is inertia a consequence of being unable to create energy, i.e., why perpetual motion machines do not in fact ...
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The relation between mass, inertia and energy

I have trouble understanding the following concept: I learnt that mass is a measure of inertia, and that seemed logical enough. Yet separately I learnt that mass is a form of condensed energy. If ...
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Do electromagnetic fields have inertia? Or, what sets the speed of light?

In all mechanical waves, there is a restoring force and an inertial influence. For example, a plucked string oscillates because the restoring force brings it back to being straight and then the string'...
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How to find the axis with minimum moment of inertia?

If a system of particles is given, in a 2D plane, with particles having masses $M_1$, $M_2$, $M_3, \ldots M_n$ and coordinates $(x_1,y_1)$, $(x_2,y_2)$, $(x_3,y_3), \ldots (x_n y_n)$, then how can one ...
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Inertia when pulling on a rope [duplicate]

Imagine a fragile cord attached to a ceiling with its other side attached to a sphere. On the lower part another cord is atrached to the sphere. Now visualize you pull STRAIGHT downward on this cord. ...
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Difference between Mass and Inertia

My questions is about mass and Inertia, what is the difference between Mass and Inertia? Are they the same or different? How? I am really confused with it,some says mass is the measure of Inertia, ...
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Are mass or inertia the same thing, the same properties?

I think so. But I wold like to know another opinions to confirm.
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Overcoming the inertia of a body at rest

Neglecting friction and other forces (air resistance) and assuming all forces are orthogonal the gravity vector , consider a large dense sphere at rest on a perfectly flat plane which is plumb. Now ...
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Total energy of an object in motion in free space

In order to impart motion (additional motion) to an object in free space, inertia "soaks up" an given amount of energy prior to additional movement, which is related to its mass, irrespective of any ...
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Can the origin of mass or inertia depend only of the gravitational field of matter? [closed]

The gravitacional field is directly proportional to mass or inertia. It doesn't have another property or field like this, with this power. I think that when we apply a force to an object, the ...
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Inertial stresses in Reynolds number

What is meant by the inertial stress in the definition of Reynolds number? Reynolds number = Inertial stress/ viscous stress
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Why do 2 bodies of different masses reach the ground at the same time? [duplicate]

Since inertia is the quantity that resists change in motion, and is represented by mass, and if two different objects are dropped from the same height, shouldn't the heavier mass accelerate less than ...
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How do I convert cardinal axis inertias to an arbitrary axis inertia?

I've tried to reduce this problem to the most basic form. I know the equation for a spring-mass system is generally: $$ F_{\mbox{applied}} = kx + m\ddot{x} \\ $$ but, in my case, I have a spring ...
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Explanation of the classic jerk and pull string system [duplicate]

It is known that when we jerk the bottom string quickly, it will break; and if we pull slowly the top string will break, while the force applied is the same. My confusion is: according to Newton's ...
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Inertia on a rotating disc?

If I toss a ball upwards in a train moving with uniform velocity, the ball will land right back in my hand. This is because the ball has inertia and it continues to move forward at the speed of train ...
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Gravity vs Electricity see-saw analogy and speed of light

Does electricity exhibit anything like the following steps: 1) A ball is rolled down from left side of a very long teeter-totter or see-saw 2) The see-saw rapidly (immediately) tilts once the ball ...
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Inertia as a fundamental interaction

Why is Inertia not included as one of the fundamental interactions, yet gravity is included as one of the four known interactions, and there is an equivalence established between gravity and inertia.
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174 views

Is Newton's third law due to inertia?

Newton's third law states that each force has an equal and opposite force. If I kicked a ball, it would apply the same force on me. Is this due to the ball's inertia? To clarify, is the ball exerting ...
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1answer
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Inertia over an airplane [duplicate]

When an airplane is traveling, it moves at the same speed as the earth does due to inertia, but since, the plane is not directly touching the globe, how does is the speed of the earth is associated ...
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What happens when a electrically charged object is moving away from a charge it is attracted to(read description) [closed]

When a electrically charged object that carries momentum and inertia is attracted to a electrical field and is moving away from it, does it lose momentum as it is pulled towards it, or does it circle ...
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How to stop the propagation of waves?

I am trying to understand Newtonian equivalent law of inertia for the waves. Roughly Newton's law of inertia says that an object which is in motion in space will continue to remain in motion unless an ...
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Is a heavier baseball bat better than a lighter one?

Baseball season is coming up and I would like to know which bat is best for me. I think the heaviest bat I can swing good would be the best, but my brother thinks the lightest bat would be the best so ...
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Will anyone please explain this problem using 4 fundamental forces?

If there are only four fundamental forces (gravity,e.m.,strong,weak) in the universe and all other forces can be expressed as a function of them then consider this problem. Suppose I throw a particle '...
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2answers
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Inertial force in a bus [duplicate]

While i am standing in a bus that is accelerating an inertial force is acting on me in the direction opposite of acceleration (I understand that). But, what is the magnitude of that force.I thought it ...
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Can I model objects as point masses when calculating rotational inertia? [duplicate]

I have an aircraft. On it are weapons. Weapons have masses and centers of masses. The larger aircraft system has a center of mass. I wish to calculate the cumulative rotational inertia of only the ...
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Sciama's paper, On the origin of inertia

In his paper "On the origin of inertia", Sciama identifies $\frac{\Phi + \phi}{c^2} = -\frac{1}{G}$ This identity has confused me because I wonder how the right hand side arises since $\frac{\phi}{c^...
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Is the inertia of light equal to the inertia of mass under $E=mc^2$?

Under $E=mc^2$, 1kg of matter has $9\times 10^{10}$ joules of energy. So, if I had just the light shining from $9\times 10^8 $ 100 Watt light bulbs inside a perfectly reflective box, would that light ...
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What is the relationship between gravity and inertia?

What is the relationship between Gravity and Inertia? Einstein told us that gravity and inertia are identical. And from the fact that two different masses fall at the same rate, I believe we can say ...
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5answers
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Is it possible to measure inertial mass without gravity or rolling?

Is there a reliable (and ideally, easy to construct+tune) method of measuring inertial mass without using gravity (e.g. weighing on a scale or a freefall apparatus or a pendulum) or rolling (e.g. ...
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Will variable but symmetrical density spheres which are otherwise identical swing at the same rate?

If you have a pendulum with the same length and different spheres on the end will the period be the same if the only variation is the distribution of mass from the center of the sphere? This is to ...
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Why do gravitational mass and inertial mass appear to be indistinguishable? [duplicate]

I have learnt that heavier the object is (the more gravitational mass it has), the more resistance to the change of motion it is (the more inertial mass it has). I can accept this fact but I can't ...
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Does Inertia “conflict” Entropy?

Earth continues to spin because of inertia. Does this fact "conflict" the entropy of the universe? Since the tendence is towards disorder, how is Inertia of planets Spin related to Entropy?
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What determines the amount of inertia of matter?

what factors would increase or decrease inertia, i.e. require more or less energy to change the velocity of matter from what is currently required all else being equal? I have heard of mach's ...
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What is the universal definition of 'inertia' in fields?

In my physics class we recently did the Gravitational Field unit, and the idea of gravitational field strength was introduced: $$g=\frac{F}{m}=\frac{GMm}{r^2}\frac{1}{m}=\frac{GM}{r^2}$$ After doing ...
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Understanding the meaning of mass in Newtonian mechanics

So, I was reading a book on mechanics and there I found the following notion about mass. It says that "Experience shows that every body resists any effort to change its velocity,both in magnitude and ...
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How does Newtonian gravity violate law of inertia?

I came across a line on http://physics.ucr.edu/~wudka/Physics7/Notes_www/node49.html " If the experiment is tried in vacuum any two objects when released from a given height, will reach the ground ...
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Clarification regarding accelerating Car with packed environment

the question is when the car accelerates the atmosphere inside that packed car also accelerates due to the inertia but in a car (with height more than 10 feet) in which superman is in no contact with ...
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What causes inertia? [duplicate]

Inertia forms the basis of Newtonian physics,but nothing really explains it.I know that it is generally accepted in classical physics,but can it's origin be explained?Maybe be relativity or quantum ...
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Would a spinning object like a fan stop faster in a non-gravity environment?

Let's say there is a fan spinning and stops in exactly 1 minute on earth. Would it stop faster or slower or exactly same time in a spacecraft without gravity but exact same density of air. Btw: let's ...
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Sensing fictitious forces

I need to clarify my understanding of fictitious forces and our sensation of them. It is my understanding that fictitious forces are terms added when Newton's laws are resolved in accelerating ...
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How should one determine the motion of extremely large extended objects?

[To put this question in context, I was reading "How much time will it take to move an object whose length is equal to one light year?" and don't really feel satisfied by the answer that has been ...
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Calculating New Velocity Vector of Moving Object [closed]

A 1kg object is moving through space. A force is applied to the object of 1N perpendicular to the direction of travel for 1 second. Assuming there are no other external forces on this object, (...
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Split moments of inertia into vectors - Right thing to do?

Let's say that we have the moment of intertia: $$J = mR^2$$ And the mass $m$ is on the $(x, y)$ position. Can I say that moment of intertia is then: $$J = mR^2 = m\sqrt{x^2 + y^2} ^2 = m(x^2 + y^2)$...
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What units is the moment of inertia for a point mass?

What are the units used in the integral equation for the point mass moment of inertia. Specifically what are the units of the double integral over a region R of $r^2· \rho· dA$, where $r$ stands for ...
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Why does a bowling ball roll down faster on a slope than a tennis ball, yet both hits the ground at the same time if they're dropped from the rooftop? [closed]

If a tennis ball and a bowling ball are dropped of a rooftop, they hit the ground at the same time. But if they are rolled down a slope, the bowling ball rolls faster. Why?