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Cause of Coordinate Acceleration in Free Fall

The acceleration on a particle following a geodesic is defined by the Christoffel symbols which are in turn defined in terms of the metric. More properly, all inertially-moving objects not affected by ...
• 484
Accepted

Is the answer given in the option wrong?

The answer sheet is correct. You are ignoring the statement “The direction of the motion of the object changed only once, at time t.” That means that the velocity was zero at time t. So before time t ...
• 103k

Issue with simplifying the equation related to non-uniform acceleration

The equation $$\frac {d v}{dt}= A+ B\, v^2$$ with constant $A$ and $B$ is an example of a Riccati equation. The Wikipedi article shows you how to solve it.
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1 vote

Do objects really "fall" at the same rate?

The effect you cite is so tiny as to be unmeasurable. This is why in most such calculations it is neglected with no loss in accuracy.
• 95.4k

Do objects really "fall" at the same rate?

You are right in that if you release from some height objects of different masses at different times, the acceleration relative to the surface (which moves with the planet) will depend on the mass of ...

Confusion over what constitutes a uniform gravitational field in relativity

a. The Rindler coordinates are sometimes referred to as a "uniform gravitational field" because they have the property of not exhibiting any tidal-forces, like a classical uniform ...
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Calculating vehicle and tire acceleration with tire slipping

I believe I've come up with the solution. What helped was separating out the wheels from the rest of the vehicle rather than treating them all as one in the FBD. Specifically, the tires are exerting ...
• 103

Forces accelerating a tire

Just consider the forces on the wheel - ignore the forces exerted by the wheel on the ground. The four forces on the wheel are: (a) its weight - your downwards red arrow (b) the normal force from the ...
• 56.1k
1 vote
Accepted

Forces accelerating a tire

I suggest a simple model to cover the no slipping and the slipping situation. Why don't the green and blue arrows simply cancel out, resulting in no acceleration/motion? Because the forces act on ...
• 97.9k

Why isn't a pseudo force considered for a block on an accelerating block?

When you analyze a system using $F=ma$ and $a$ is non-zero, that doesn't mean it is not an inertial frame. You are analyzing the motion from the "laboratory frame" attached to the floor, ...
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What is the gravitational force acting on a massless body?

As the question points out correctly, mass cancels out leaving the acceleration; a=GM/r^2. Thus, massive or massless- it doesn’t matter. This was observed as far back as John Philoponus in the 6th ...
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Why should an electron falling into the nucleus, according to the Maxwell's laws of electrodynamics, destroy the atom?

It is often said in physics and chemistry classes and textbooks that atoms must be unstable when the electron continuously loses energy and finally fall into the nucleus according to classical physics....
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Why should an electron falling into the nucleus, according to the Maxwell's laws of electrodynamics, destroy the atom?

The protons and electrons do not annihilate. They combine to form neutrons. When a neutron star forms, the enormous pressure from a supernova explosion forces the electrons into the nucleus. The ...
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Why should an electron falling into the nucleus, according to the Maxwell's laws of electrodynamics, destroy the atom?

It is often said in physics and chemistry classes and textbooks that atoms must be unstable when the electron continuously loses energy and finally fall into the nucleus according to classical physics....
• 39k

Why should an electron falling into the nucleus, according to the Maxwell's laws of electrodynamics, destroy the atom?

They often give an impression that the two when combined would annihilate into energy. - No, that is not what is meant. Classically because the electrons are charged and accelerating, the electrons ...
• 97.9k
1 vote

Does force cause acceleration or acceleration cause force?

Former philosophy student, current physics student here. This question is perfect since it pertains to the mathematical principles of natural philosophy. I can answer your question directly: it is ...

Newton's laws on constant velocity

In classical mechanics, the total mass of a closed system is conserved (constant). So necessarily $\frac{dm}{dt} = 0$, and the laws hold. In the case of a rocket, however, we might ignore the mass ...