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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How does inertia affect an object suspended in a fluid?
When I asked my physics teacher how fully submerged objects are suspended in fluids, she told me it was because the object's density was equal to that of the fluid's as a result of the net force ...
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Calibrating an inertial measurement unit (IMU) to zero/flat surface
I am building a digital spirit level using an inertial measurement unit (IMU), and I want to calibrate the device so that it shows the angle correctly. Does anybody here have experience with this kind ...
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The principle of stationary action from the principle of inertia?
Can we infer the principle of stationary action from the principle of inertia that causes a mass particle to resist changes in its momentum? The following is my own speculation.
When a mass particle ...
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Why are the masses hanging from a pulley not considered in its moment of inertia?
My physics textbook showed a diagram of a pulley with mass with 2 blocks hanging from either side by a massless string. They calculated the moment of inertia by finding an approximation of the pulley ...
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Observational status of Sciama's hypothesis
I have always taken the existence of inertia more or less for granted, as an observational fact that does not require explanation.
But on reflection this is an unscientific attitude, and perhaps there ...
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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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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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Inductance - a better analogy than the fact that it is similar to inertia
This question is to get a feel and good definition for what inductance actually is.
I have read about the analogy where inductance can be compared to inertia-that the flux through an inductor resists ...
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How are objects kept free falling in the LISA experiment?
I'm watching a video about the LISA experiment, which will be used to detect gravitational waves.
In there, three space stations will be launched and will follow the Earth in its revolution around the ...
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How do I convince my students the Newton's first Law is the way it is?
Every time I teach this law, there are always a few students asking me why a net force is zero on a system moving at a constant velocity. This group of students takes physics for the 1st time. It is ...
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How density of fluids is would affect inertia?
I was watching that movie Event Horizon and they use water as an instrument to protect passengers of a space vessel from 30G acceleration, so my question is about a similar scenario, what would happen ...
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Newton: an object in motion remains in motion: was there anyone else who believed this? [closed]
From my own experience as a schoolkid, that was the law that I was not buying. I could see his understanding of the Lunar orbit making him think this but otherwise, what in human experience would lead ...
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Equivalence of Inertia and Gravity [duplicate]
I'm now wondering...does - energy=mass=inertia=gravity? Are they all, intrinsically, the same, "thing"; that is, the same, "entity".
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How does classical, Newtonian inertia emerge from quantum mechanics?
From my understanding, inertia is typically taken as an axiom rather than something that can be explained by some deeper phenomenon. However, it's also my understanding that quantum mechanics must ...
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How to mathematically express and then optimize my photon emitter? [closed]
A laser shoots photons directly at a flat disk with a fixed linear rate f(t) on the interval [t0=a,tn=b] with a horizontal path.
E.x. f(t)=100 photons per second
The laser is controlled by robotic ...
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Mass definition
One definition of mass is 'a measure of the quantity of matter in an object at rest relative to the observer'. What do 'at rest' and 'relative to the observer' mean here? I know it has to do with mass ...
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How can you figure out when inertia or momentum is keeping the object in motion?
If we consider the case of Earth, inertia carries the Earth forward (inertia alone will make the Earth go out of orbit so gravity keeps it in orbit around the sun), but if we consider the case of a ...
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Regarding the law of Inertia
I am still a student in high school, so don't judge me because of this question:-
Imagine you are on a train, then you pass by a tree; for me, this tree appears to me in motion. The train has moved ...
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I have a question about explanation of inertia of motion of a body by pseudo force
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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Explaining how the Higgs fields gives particles mass [closed]
Physicists say the Higgs Field is like syrup and slows particles down from the speed of light. Wouldn’t it be easier and more correct to say there are no particles, just fields, and the strength of ...
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When we say inertia is the quality of matter to resist changes in velocity, in what way does it 'resist'?
Until today I used to understand and explain anyone the concept of inertia in the following way, but I found a loophole in that explanation.
Explanation :
Imagine we take a body in space where there ...
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What is the origin of the inertia?
Is there any explanation why it is harder to move an object with more mass than an object with lesser mass? What kind of force is opposing our force? Is it finalized currently and well known what the ...
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Can we have motion in systems where inertia is neglected? [closed]
According to Newton's law:
$$ \sum F=ma$$
So, if we have some acceleration, it's because we have a certain amount of motion in our systems.
This makes me confused if inertia was neglected. Are there ...
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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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Do electrons have inertia?
I don't know quantum mechanics and know a little bit about mechanics and a very little bit about subatomic particles but I am just a curious to know the answer to my question. My question is if '...
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Why is inertia connected with mass and not momentum? [duplicate]
When my teacher was teaching us $E=mc^2$, he told us that the relativistic mass of an object increases when the speed increase. He told us that it is due to the increase of inertia. He said that as ...
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Thought experiment in Mach's principle - Can a void universe be considered with special relativity?
Mach's principle is based on a thought experiment in which an astronaut floats in the middle of a space devoid of all matter and all landmarks. No star, no source of energy is present, whatever the ...
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Electromagnetic Waves and Inertia
I have a conceptual question. Suppose we have two bodies of equal masses. One is electrically neutral and the other is electrically charged (positivley charged). Now we apply equal magnitude of force ...
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Would you run faster on Mars?
Given the 1/3rd of Earth's gravity on Mars and neglecting space suit limitations and also assuming you have maintained your muscle strength, would you run faster on Mars?
The answer may not be so ...
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Is inertia present at the level of elementary particles?
Is a more massive elementary particle will experience more inertia in a one-on-one particle interaction?
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How to find inertia tensor of a circular ring from angular momentum and velocity?
Consider a thin circular ring with radius $R$ and axis of rotation as shown in the figure. If $\vec{L}$ denotes angular momentum and $\vec{w}$ is the angular velocity then
$$\vec{L}=\begin{bmatrix} I_{...
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Are there two competing definitions of "inertia"?
The term inertia is often introduced by stating Newton's first law: An object stays at rest or moves with $\vec{v}=const.$, if the resultant force is zero. This feature of masses is called "...
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Why does "net force" being zero not mean that the parachuter becomes stationary in the atmosphere?
Take the typical phyiscs / classical mechanics example of a parachuter descending at constant speed. The two forces acting on the parachuter are weight, which has direction towards the ground, and air ...
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What happens to the acceleration from an initial force according to the law of inertia?
Say we hit a golf ball with a club. Hitting the ball requires a force = m*a. According to the law of inertia, velocity should be constant, but how can that velocity be constant if we hit the golf ball ...
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Why does the distribution of mass affect the resistance to being pushed aka inertia?
So I know that the mass of distribution of an object affects inertia. But the question I'm asking is WHY. And having fancy formulas for me is not actually answering the WHY, it just confirms it. So If ...
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Taking drag into consideration, how does mass affect horizontal range given that the impulse applied is always the same? [closed]
If two objects, one light and one heavy but otherwise identical, are given the same impulse from rest and begin to travel horizontally through a resistive fluid, which object makes it farther?
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In the Langevin dynamics: neglecting inertia. A mathematician trying to understand physics terminology
If we write the Langevin equation: for a particle with mass $m$, position $x$ and velocity $v$, with some damping coefficient $\gamma$,
$$ m dV(t)=-\gamma V(t)dt+dW(t) ,~~~~~~~dX(t)=V(t)dt.$$
Then as $...
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Why are there so many fundamental differences between contact forces and gravity?
I had this very fruitful conversation about the inertial motion of charged particles on gravitational/electric fields.
A field force like gravity, can't be felt, it does not produce proper ...
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Is the motion of an electron bound into an atom inertial?
When a particle moves on a gravitational potential subject to no contact and tidal forces, the particule clearly is in inertial movement.
But what about the "motion" of an electron bound ...
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Equivalence principle, geodesics, and proper acceleration are exclusive to general relativity, or they can be understood in classical mechanics terms?
I have been told that "inertial movements, or distinction between proper and coordinate acceleration don't have meaning out of GR".
But now I'm confused, I always though of these concepts in ...
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Which is true: objects keep spinning because of inertia, or objects keep spinning because of centripetal force?
I'm hoping any gravity or friction can be ignored.
I gather a spinning object is a non-inertial frame. I suppose that's because change of direction is acceleration. Continued acceleration requires ...
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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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Has anyone directly observed the equivalence of inertial and gravitational mass for the electromagnetic force?
Before someone tells me to drop a bowling ball and feather off the Leaning Tower of Pisa in a vacuum, let me point out that, in general relativity, you can't deduce anything about either mass of a ...
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Why is a larger force needed when you decrease the distance in regards of torque? [closed]
I think it's because of inertia.
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Torque and moment of inertia with bikes
Can someboby please explain to me why it is better for a bicycle/ motor cycle to have lower center of mass when it rounds a turn.
What I could gather from the rule I = mr2
Was that the arm is shorter ...
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How many types of inertia are there?
I was looking for types of inertia, but I am confused. My book says there are three types of inertia, namely inertia of rest, inertia of motion, and inertia of direction. But when I searched for these ...
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Gravitational and inertial mass seem to result from different fields, yet virtually the same. How do new physics theories attempt to reconcile this?
As best I understand it, internal mass (at rest) is due to interactions of particles with the Higgs field, and in equation terms, due to various chiral terms, sometimes described as swapping chirality....
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Why can we calculate moment of inertia, but not inertia?
I'm learning about rotational motion and the moment of inertia. Unlike inertia that I learned before, there is a formula to calculate rotational inertia. I'm having trouble understanding why it's ...
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Why don't we use momentum to quantify inertia?
My understanding of Newton's 1st and 2nd laws have led me to believe that inertia and momentum are the same.
1st law: An external force is required to overcome an object's inertia
2nd law: Force is ...
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The moment of inertia of a hollow cylinder is lower than that of the "corresponding" solid cylinder (same density, outer radius, height):
This is a self-answered "question" for those scratching their heads after learning, e.g. in class, that the moment of inertia of a hollow cylinder is higher than that of solid cylinder. Note ...
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