Questions tagged [relative-motion]
Use this tag for questions related to how objects move relative to other objects dependent on your frame of reference, and how this applies to special relativity.
85
questions with no upvoted or accepted answers
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Sum of geodesic deviation around a triangle in curved spacetime?
So I was pondering about geodesic deviations and I'm confused about the following. Let's say I have $3$ geodesics $\gamma_1(t)$ , $\gamma_2(t)$ and $\gamma_3(t)$. I introduce a parameter $s$ such that ...
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How to derive relative velocity in two particle scattering?
While calculating the scattering cross section for one particle scattering we use the formula $$J_i=\rho v$$ where $\rho$ is the density of the incoming beam and $v$ is the velocity of the incoming ...
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Scalar versus invariant in Newtonian mechanics
I looking up coriolis transport theorem for rotating refrence frames and while reading through this derivation he wrote:
In Newtonian mechanics, scalar quantities must be invariant for any
given ...
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Upstream and downstream problem using relative velocity
On a river coast, there is a port; when a barge passed the port, a motor boat departed from the port to a village at the distance $S_1 = 15$ km downstream. It reached its destination after $t = 45$ ...
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Should the velocity increase or decrease?
Suppose some projectile is traveling along the positive $x$ direction at a velocity $v$. While moving it is emitting particles, and thus losing mass. If the particles are being emitted in the same ...
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Would impact angle matter on relativistic impactor?
I'm trying to calculate (for fun) a comparison between a kinetic impactor and an H-bomb.
I would assume this to be a fairly straight forward problem involving kinetic energy and a table of various H-...
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Does relative velocity apply before or after the impulse?
I'm solving the following question from Kleppner and Kolenkow:
My solution differs from the textbook solution not only in the magnitudes in parts (a) and (b) but also the conclusion in part (c). ...
- 1,571
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Coordinate transformation and absolute motion in general relativity
In special relativity, all motion is relative. But in the presence of black hole, all motion is with respect to black hole. The curvature of spacetime depends on how far we are away from the black ...
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Attempting to solve the twin paradox without acceleration
My teacher told me that the key to solve the twin paradox is acceleration of the one that travel away. However, I feel a little bit uncertain that time change significantly by just a slightly nudge of ...
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answer
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Principle of Relativity and the invariance of Newton's law in IRFs
Newton's law are form invariant under the coordinate substitutions:
$$
\tilde{x^{i}}=x^{i}+a^{i}
$$
This means that Newtons' equation of motion,
$$
F^{i}=m \frac{d^{2} x^{i}}{d t^{2}}
$$
(where $i=1,2,...
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1
vote
1
answer
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Relative velocity and proper time derivative of geodesic deviation?
From wiki
To quantify geodesic deviation, one begins by setting up a family of closely spaced geodesics indexed by a continuous variable s and parametrized by an affine parameter $\tau$. That is, for ...
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Is e (COR) defined for whole situation or just during collision
According to wikipedia
$${\text{Coefficient of restitution }}(e)={\frac {\left|{\text{Relative velocity after collision}}\right|}{\left|{\text{Relative velocity before collision}}\right|}}$$
...
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vote
1
answer
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Linearly Interpolating in a Non-Inertial Frame
I am working on an engineering task where we have a flying object which knows its height above a curved surface as well as how close it is to other flying objects. If I want to interpolate between two ...
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Work done on a moving cart in wind
Let us suppose a cart is moving in a rough ground with a propeller attached to the roof of the cart.
Let the velocity of the cart at the given point of analysis be V and velocity of wind is -W. The ...
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How does motional EMF emerge from Jefimenko's Equations?
I have been using Jefimenko's Equations for determining the electric and magnetic fields of a conductive coil with a (possibly changing) current. For most situations of interest this can be done to ...
