Questions tagged [distance]
The distance tag has no usage guidance.
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How can I find the distance someone moves with the effects of deacceleration due to friction when im only given the change in velcoity from time? [closed]
I was given a problem to work on that said to calculate how far someone moves as they slide across the floor and with the effects of friction acting on them. However, the only variables they gave me ...
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Which experimental setup replicating Michelson-Morley experiment had the longest path of light?
After the Michelson-Morley (MM) experiment many scientists performed similar experiments using the original MM experimental setup, or different derivative experimental setups employing lasers and ...
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How does the definition of a rigid body imply constant distance from the center of mass?
Let there be a system of N point-particles in 3D space, this system is a rigid body. The general definition of a rigid body is $ \mid r_{i}-r_{j} \mid$=constant $\forall i,j$
In one of the books I was ...
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How to determine whether an object is a point object?
I know that we can consider an object as point object, if its size is negligible as compared to distance traveled by it in reasonable amount of time. But in my book Ncert there is questions which asks ...
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How can we accurately tell distances of celestial bodies when considering superluminal expansion [closed]
If parts of the universe are moving away from each other faster than the speed of light relative to my position in space, how can we accurately tell the age or distance of other celestial bodies ...
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Where does the negative signature case come from in the Pythagorean derivation of distances in spacetime?
I am reading Why does $E=mc^2$ (and why should we care?) by Brian Cox and Jeff Forshaw. I want to understand these three sentences
(from page 76/77):
Once we follow Occam and make these two ...
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How does loudness decrease with distance? [duplicate]
Let's say there's a speaker in a huge open space on the Earth's surface. The speaker blares a sine wave with frequency $f$ Hz and and volume $V_0$ decibels.
How does the volume (in decibels) decrease ...
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How can we calculate distance of Light? [closed]
Say I am using torch , and I want to calculate distance of light it travelled if I put it upwards , how can I calculate the distance of light ?
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What symbol is used for 'proper distance'? [closed]
Proper time and proper space are generally defined as what an observer would measure in their own rest frame. If $\tau$ is a commonly used symbol for the proper time, what is the corresponding symbol ...
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I need a ship at rest to accelerate under preferably constant acceleration/deceleration to arrive at rest at an object 55 AU away [duplicate]
I'm working on the story and I need help with the plot point. Assume that the energy needed for constant acceleration is not a problem. And there's no need to complicate this with outside forces.
I ...
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Need clarification/input on a curvature dilemma
Even though I said I'd never waste this much energy arguing with a flat earther, I have a dilemma and need input.
I'm in the Vancouver, Canada area. I've been shown a picture that the person claims is ...
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Definite integral that give distance between two moving particles
I have two particles $P_1$ and $P_2$ and I know how their coordinates change against time $(x_1(t)$, $y_1(t))$ and $(x_2(t)$, $y_2(t))$
I can easily get distance $L$ between them as
$$L(t)=\sqrt{{(x_2(...
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Radial distribution function of particles in water at room temperature
I am trying to figure out some experimental effects I'm seeing, and I hypothesize that what I'm seeing is due to particles interacting with each other (which I neglected, hoping that I didn't need to ...
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If two opposing equal forces act on an object, how does one calculate the energy exerted? [duplicate]
If energy exerted is a function of distance and force, the object would not move in this case. But would energy not still be exerted?
Simplified the example for sake of clarity; but specifically ...
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Simple distance calculation in General Relativity
So imagine a spacetime with the Schwarzschild metric:
$$ds^2=-c^2\left(1-\dfrac{2GM}{c^2r}\right)dt\otimes dt+\dfrac{1}{\left(1-\dfrac{2GM}{c^2r}\right)}dr\otimes dr+r^2\left(d\theta\otimes d\theta+\...
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Can a big enough Giant travel many lightyears in just a few seconds? [closed]
We, as humans, given our height and size, view the world from the same general perspective. An ant, on the other hand, will understand the same world in a completely different way, given how limited ...
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What distance (comoving, proper, light travel time distance) does the cosmic distance ladder actually give us?
In most material I can find on the cosmic distance ladder for a lay-level reader like myself, it never seems to explicitly say what distance its talking about.
There is the proper distance when the ...
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Is the unit $m^2$ for area size ambiguous? [closed]
In normal case, we use $m^2$ to represent the size of an area - the product of two distance whose corresponding quantities are perpendicular. But it can also be simply the square of one distance, such ...
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Why is relative velocity not defined on curved manifolds, is relative distance also not defined?
I understand that relative velocity is not defined on curved manifolds because you are comparing vectors from different tangent spaces. Lets say body A is moving vith velocity $v_A$ and body B with ...
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Explain the equation
Can someone explain me this equation. This is braking distance equation that applies all reaction times ect.. Taken from Bosch Automotive Handbook.
But what does the 25,92 mean there?
v= velocity
tvz =...
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Do most distant objects on the Hubble diagram 'tell' as the Hubble constant has been valid for at least 60 million years?
As we all know the deeper we look into the space the further we look into the past... So if the Hubble diagram shows the most distant objects at a 20 Mpsec or ~60Mly distance from us (and as for not ...
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Time dilation under constant acceleration
If I am given:
the distance of two points
the (constant) force being enacted on the object moving between those two points
how can I figure out:
the time it would take the object to reach the other ...
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Estimating penetration depth of projectile in nonhomogeneous material
I need an equation for calculating the penetration depth of a projectile in a non-homogenous material. I have the values for density of each layer and the projectile, speed, and angle. Does anyone ...
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What if everything doubled linearly? [duplicate]
There is a question that goes:
Suppose you are told that the linear size of everything in the universe has been doubled overnight. Can you test it by using the fact that the speed of light is a ...
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Can a distance function be derived from a displacement function?
If I have some function $\vec{x}(t)$ that represents the displacement function for some object $x$, is it possible to derive a distance function $d(t)$ for that same object, representing the total ...
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How do you find the time an object stops per hour after getting the maximum speed, and average speed that accounts for stop time?
A bus travels at 54.0 km/h while moving but after accounting for stopping time, to let passengers on and off the coach, it averages a speed of 45.0 km/h. How many minutes does the bus stop for each ...
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Does work done by a non-conservative force involve distance rather than displacement?
I am a new physics teacher and struggling to piece out the nuance of work calculations for my Advanced Placement (AP) students.
I feel like after a fruitful year of distinguishing between vector and ...
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How distance affect wind speed from a fan?
I noticed that when you feel the wind force from a fan close up, it feels like more force than from far away. Can someone give me an equation, where given a base wind speed $v$ in mph of the fan, and ...
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Concept of distance in cosmology
I am trying to follow some calculations in the book Cosmology by Daniel Baumann, where we have a light source and an observer, and we need to compute the area of a sphere centered at the source and so ...
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Does work done by/against friction depend on path length or displacement? [closed]
On an equipotential surface, does the work done in moving/sliding a block of mass depend only on the initial and final position or the circuitous path (notwithstanding work done by or against friction ...
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Distance $r$ between galaxies inside the galaxy cluster
I am currently working on the dynamics of the galaxy cluster, so i am trying to get the distance $r$ between the galaxies inside the galaxy cluster from its centre. As a input i have RA , DEC and Z ...
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Is Hubbles law due to Gravity?
Hubble's law states that Distance is proportional to Velocity. A ScienceDirect article states that Classical Hubble expansion is characterized by a proportional increase in the rate of expansion ...
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Calculating distance to galaxies seen through a telescope
When we see a galaxy through a telescope, say the James Webb telescope, it is said we see a galaxy as much as about 10 billion light years away. But 10 billion years ago we were much closer (because ...
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Difference between average position of electron and average separation between proton and electron [closed]
I'm not sure to understand what is the difference between those 2 terms in the hydrogen atom.
The average position $\langle \hat{\bf r} \rangle$ is written $\langle \Psi^{*}|\hat {\bf r}|\Psi \rangle$,...
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Is clause "distance doesn't depend on frame of reference" an axiom in Newtonian Mechanics?
Consider 2 object is 1 and 2, at time t1: 1 has position is C and 2 has position is A.
In frame of reference 1 (1 is stand still), from time t1 to time t2, 2 moves from A to B
In frame of reference 2 ...
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How can the distance to the Sun from the Earth be determined without relying on any prior baseline measurements?
I am asking if there is a way that a man could determine the distance from the earth to the sun without already having a baseline distance or dimension measurement to begin with, and without having ...
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Energy conservation, photon, distance
From Weinberg 1972 Gravitation and Cosmology Principles, when discussing the luminosity distance, he talked about due to light wavelength being stretched as well as time interval stretched, in the &...
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The "overlap function" of a $Z_2$ gauge theory
Consider a $Z_2$ gauge theory on a square lattice (Ising spins on edges) with classical degrees of freedom, i.e.
\begin{equation}
E = -\sum_{\square} \sigma_i\sigma_j\sigma_k\sigma_l
\end{equation}
...
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Proper distance in terms of the deceleration parameter
So, in an effort to connect theory to measurable quantities, in the Ryden cosmology textbook the scale factor is Taylor expanded as $$a(t) \approx 1 + H_o (t-t_o) - \frac{1}{2}q_o H^2_o (t-t_o)^2$$ ...
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Equivalence between small distance and high energy
I see in a lot of particle physics literature statements along the lines of: 'This is valid for high energies (small distances)'. Exactly what do we mean by small distances in this case? From QFT, QM ...
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Distance in Hubble law vs special relativity
Came across this very informative website https://astro.ucla.edu/~wright/cosmo_02.htm , and it has the following two diagrams. I'm having trouble figuring out why "But the Hubble law distance $D_{...
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Light emitted at $t = 0$
So solving for the scale factor from the Friedmann equation we can then use it to calculate proper distance via
$$d_p(t_o) = c \int_{t_e}^{t_o} \frac{dt}{a(t)}$$
For a particular universe $a(t)$ is ...
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Number of meetings of $2$ cars starting from opposite ends of a road [closed]
Question:
$2$ cars travelling at $108,75$ kmph respectively, start from the opposite ends of a $90$ km straight road. Travelling back and forth continuously for $10$ hours, how many times do the $2$ ...
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How far could I travel in distance if I jumped off the ISS outward into space? [duplicate]
How far would I travel if I were on the ISS and jumped outwardly into open space?
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How to denote mass and distance approaches to zero?
I saw in a physics book that one denotes that mass and distance approaches to zero as $m\to 0$ and $d\to 0$. Is this correct or should one denote these as one-sided limits $m\to 0^+$ and $d\to 0^+$?
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How can you determine distances to obejcts further away than 13.72 billion light years?
I was checking out this calculator where you can calculate distance to distant astronomical objects from redshift.
Here are some values:
z=0.1 > distance (light travel time) 1.31 billion lightyears
...
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Derivative of distance [duplicate]
I know that $speed = |\frac{\vec{dr}}{dt}|$
and first derivative of distance with respect time will be $\frac{d\vec{|r|}}{dt}|$
These 2 expressions don't seem to represent the same thing. But when I ...
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Finding rate of change of the distance from an observer on earth to a satellite in orbit
This is a satellite motion related question. To give context, imagine a satellite orbiting Earth at a distance 'R' from the center of the Earth at constant velocity 'v'. An observer on the surface of ...
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Is a meter constantly getting bigger? [duplicate]
If the bigbang is the start of the expansion of space everywhere then does that mean that a 1 meter ruler is bigger tomorrow than it was today?
Does this apply to the size of atomic particles and ...
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How could proper distance today be infinity in a curvature only Universe when the age is finite?
So for a curvature only universe, the Friedmann equation becomes
and we get the solution $a(t) = t/to$, and $to = 1/Ho$.
If we calculate the proper distance today we will get
As $z-> infinity$, ...
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