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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!

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! In those cases use the tag instead.

464 questions
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Is there still no known origin of the law of inertia?

To quote Feynman at about the 21 minute mark of the first Messenger Lecture on The Character of Physical Law, ...that the motion to keep it going in a straight line has no known reason. The reason why things coast forever has never been found out.…
Armadillo
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Why does inertia happen?

In this video R P Feynman relates a story where his father told him that, even though we know the word "inertia" and what it means, nobody knows why inertia happens. Is that still true?
isomorphismes
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Can we catch a bullet in a gun barrel? If not, why not?

I have looked through various questions about guns and bullets but I haven't found this one. If someone fires a handgun there is a recoil. Shooters learn to control this, the gun does not fly out of their hand. Surely if a bullet is fired accurately…
chasly - supports Monica
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If a vehicle (bus, train) rapidly stops (or accelerates, or turns), why don't our hair or clothes move from the inertial force?

Many times I was sitting in a train, watching closely nearby people. If the vehicle changes it's movement rapidly (brakes, turns, etc), then obviously, people feel the inertial pseudo-force that might even make them fall. They don't fall, however,…
gaazkam
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Can someone explain to me inertia?

I'm a little new to physics and I'm not quite getting the concept of inertia. Can someone help me?
Joe Pigott
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Have you ever seen in your car a mosquito? it's not capable of going 60 mph. How come it can still keep up with the car as if it weren't trying

For instance, a fly is staying at the same spot, then your car suddenly moves forward at a rate of 60 mph. The mosquito IS staying at the same spot but for some reason it moves along with the car as if nothing happened.
Benny Tong
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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 quite a distance and the tree is no longer in…
hari krishnan n
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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 say the radius and mass of each sphere is identical…
CoryG
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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, acceleration and/or velocity, force, exert (this…
user130306
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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 principle but that seems to not be accepted. What other…
michael
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