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 or inertia tensor!
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Newton's first law and Inertial systems
Newton's first law is part definition and part experimental. Isolated bodies move uniformly in inertial systems by virtue of the definition of an inertial system. In contrast, the assertion that ...
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Can someone explain 'virtual mass' in fluids in simple words (for a dummy/high schooler)?
so I recently came across the term 'virtual mass' and when I looked up more about it, it just gave me some stuff about fluid mechanics that I dont understand properly. My understanding of virtual mass ...
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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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Does it make sense an inertial mass dipole moment for massless particles?
Electric and magnetic dipoles exist in nature even with zero net electric and magnetic charge
Electrons have a unit of charge, about $10^{-31}$ kg of inertial mass, zero electric dipole moment, $\...
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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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Can added mass depend on stochasticity of motion?
Can added mass (also called virtual mass or induced mass) of a voluminous object in a massive fluid surrounding be affected by some stochastic motion of the mass (relative motion between the object ...
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Why does the ball in Galileo's double inclined plane experiment reach the same height?
Why does the ball in Galileo's double inclined plane experiment reach the same height? I know how to show it by energy conservation law but am unable to prove it by the equations of motion. Can anyone ...
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What is happening on an atomic level (or lower) when a object is in motion (inertia)?
If you have an iron ball and throw it upwards you are imparting a force which opposes gravity.
Initially this force is easily understood by your hand pushing the ball upwards, so the atoms in your ...
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Inertial movement of a body on the surface of a planet being dragged away
When we stand still on the surface of Earth, this is clearly a non-inertial frame.
Inertial frames of reference are characterized by accelerometers measuring zero, so you fell weightless when you: 1) ...
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Equivalence among three kinds of mass
If there are three kinds of mass
(1) resistance (classical inertial mass, rest mass)
(2) sensitivity to gravity (weight)
(3) creation of gravity,
the Eotvos experiment shows the proportionality ...
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Relation between Fisher Information Matrix and Inertia Matrix
I have been wondering whether there is a relation between the Fisher Information Matrix in a stochastic particle system and Inertia Matrix?
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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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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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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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Avoiding inertial affects by accelerating larger mass in 2 body system
Suppose two bodies S and L are in proximity (asteroids say). L is substantially larger than S. For simplicity, let them initially have negligible angular and linear velocity.
S will begin to fall ...
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calculation of moment of inertia referred to motor shaft?
Is this equation valid for a given mechanical system
The Inertia of the motor is $J_m$,there is no loss in the system.then conservation of energy can be used.
the motor is revolving with speed $\...
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Influences on wavefunction path analysis
I was looking at simulations of a wave going through a slit. When the wavelength was much smaller than the slit width, the wave went through the slit and kept going straight like a laser beam. But ...
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A trio of spinning marbles
My little brother showed me this devised act in which he stuck three marbles in a triangular pattern
When he spun any of those marbles, the triplet would first rotate normally, but moments later, ...
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What is static mass increase effect predicted by General relativity?
According to wikipedia, static mass increase is predicted by Einstein's General Relativity. In the book 'The Meaning of Relativity' by Einstein, inertia will increase when the object is near a ...
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Closed-form equation for orientation and angular velocity over time
If a rigid body, rotating freely in 3d, experiences no friction or other external forces and has an initially diagonal inertia matrix $\mathbf{I}_0$ (with $I_{11}>I_{22}>I_{33}>0$) and ...
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Calculate Rotational Intertia
If a can of soup, and a can of beans (tightly packed), are set in a race down a rough hill (has friction), the soup wins, because the inside of the can (soup) is not drawing energy from the system.
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Mass moment of inertia flipping in different mediums
Consider someone performing a front flip in the water versus in the air. Assume the body position in both cases to be identical. In which case would the mass moment of inertia be greater and why?
Prof ...
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In a moving car / bus when the car suddenly accelerates do we go back due to inertia or is it due to pseudo force?
When an car moves forward we go back and we have always read that the reason was that our legs stay in contact with the ground and our body goes back since it was at rest and with sudden motion it ...
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Maxwell's wheel - moment of inertia vs damping coeff
I am investigating the relationship between the moment of inertia of a yoyo-like apparatus (maxwell's wheel) and its damping coeff. I am adding disks to my yoyo to change its moment of inertia, which ...
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What is exactly particle inertia in a fluid-particle mixture?
In a mixture of a cylindrical particle and the carrier fluid, what exactly particle inertia refer to? (let's neglect gravitation force and Brownian motion).
When the size of particles are small (...
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What's the reason an airplane turning 180° from strong headwinds causing it to have no ground speed does not stall?
I saw a video of a small propeller plane hovering over the ground due to strong headwinds but then turns 180 degrees and flys away. I was trying to figure out if the plane shouldn't be stalling ...
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Doubt regarding lifts (and inertia?)
so i was thinking about lifts and i am confused.
let's say there is a body within a lift (system at rest). Now if the lift starts to accelerate downwards with say an acceleration a ($a>g$). The ...
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Why we can take for granted that energy binding is associated with inertial mass?
It is common to state that a proton is bounded state of three quarks, and that the QCD energy binding (associated to a "cloud" of gluons joining together the three quarks) is responsible for ...
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Propellant less propulsion when there is nothing to push against
Is there a way for a vehicle to move without losing mass when there is nothing for the vehicle to push against? For example, a helicopter flying around in a vacuum.
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Is the jerk caused by pseudo force when bus come to stop suddenly?
If a bus stops moving suddenly, we tend to fall forwards due to the inertia of motion of our upper body.
But can we explain the sudden jerk in the forward direction due to some pseudo force? (Because ...
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Inertia tensor but expressed after undergoing rotation
Suppose we find a set of basis that constitues the principial axis of some three dimensional body with mass. In this set of basis, our inertia tensor becomes a diagonal matrix, let $I' = diag(I_{x'x'},...
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Red shift/Blue shift as a standard for determining absolute motion
If I begin standing, I can imagine that there are photons of various wavelengths arriving at my location from all directions. If we eliminate local energy coming from stars and radiating bodies, ...
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Walking pace and torque
How to understand the relationship between the mass of a person, the length of the legs and the walking pace? My professor tried to explain it but I didn't quite get it.
So we can consider the hips as ...
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Why does rotational inertia represent the resistance of a body to angular acceleration
I understand how rotational inertia, $I=mr^2$, is defined based on $\tau_z=mr^2 \alpha_z$ as an analogy to the linear inertia $m$. But I'm still not sure why it represents the resistance of a body to ...
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Electromagnetic inertial reaction force?
I accelerate charged particle $A$ causing virtual photons to travel to distant charged particle $B$ which feels an electromagnetic force proportional to $A$'s acceleration (for a classical field ...
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Changing effective mass of electron using electric potential?
The Dirac equation for an electron in the presence of an electromagnetic 4-potential $A_\mu$, where $\hbar=c=1$, is given by
$$\gamma^\mu\big(i\partial_\mu-eA_\mu\big)\psi-m_e\psi=0.\tag{1}$$
I assume ...
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An expanding, sliding charged tube's self-imposed electromagnetic induction
If I have a simple cylindrical electrically-insulating tube possessing a net electrostatic charge and allow the tube to slide parallel to the tube's axis, that tube will possess electric currents ...
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How to calculate the tensor of inertia in this problem?
I have the following geometry for my problem:
I'm asked to calculate the tensor of Inertia:
$\stackrel{\leftrightarrow}{I}_{O}=\left[\begin{array}{ccc}{I_{11}} & {-P_{12}} & {-P_{13}} \\ {-...
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Isn't inertia experience by person in moving bus same as torque
When a bus moves suddenly, the person standing in it tilts backwards. This concept is explained using inertia(tendency of body to resist change in its state of motion) but when the bus moves suddenly, ...
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How does the inertia of granules within a rotating cylinder affect its inertia?
If a cylinder is partially filled with granules and is rolling down an inclined plane, is there any relationship between the rotational motion of the granules and the motion of the cylinder? I'm ...
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Calculating inertia of motor
I'm currently working on a project, and for futher calculations down the road (the controller of the mechanical system) I need to calculate, as accurately as possible the interia of the system.
I'm ...
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Calculate stroke force and angle for a ball rolling on a surface to reach a destination position (optimal golf putt)
I'm trying to find an algorithm which calculates the optimal golf putt (angle, force) given a 3D surface (obtained through Poisson reconstruction), start and destination position (hole). I guess that ...
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What's the seconde moment of a T beam with a heel?
the seconde moment of area of a rectangle is
Iy = (bh^3)/12
b : base
h : height
What is the second moment of area of a T beam like this one ?
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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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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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Angular velocity of disc from induced motion
I came across a question regarding linear momentum $L$ and it's conservation, however I tried and got confused. It reads: A $40kg$ girl stands on the very edge of a rotating disc of mass $50kg$ and ...
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Properties of inertia regarding soft boil egg and hard boil egg
If you have two spinning eggs on top of a table, and one of them is hard boiled and the other is raw, how can I analyze this from the perspective of inertia.
I'm asked to include the terms inertia, ...
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Inertial pressure on in a rotating syringe
First question on stackexchange. Hopefully somebody can help me out. I'm struggling to express the following eloquently.
I have a rotating syringe tipped with a needle. rotation speed w, with radius ...
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Doubt in law of mutual interaction
Book: Classical mechanics (textbook) by Douglas Gregory (cambridge publications)
Law of mutual interaction states that when two particle (let it be P1 and P2) interacts, the particle (P1) induces an ...
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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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