Questions tagged [geometry]
To be used for questions on geometry closely pertaining to physics. Includes differential geometry and Euclidean geometry. Do prefer the more specific tag differential-geometry for questions about differential geometry.
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Rate of change of surface area is acting weird
Preface- I made this situation up. An uniform metal sphere of given mass $M$, is being continuously fed more mass at its centre at the rate $4 \ \text{kg/s}$. If the density stays constant, find the ...
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Is there a general solution to all spherical triangles as described by Arnold Sommerfeld?
Arnold Sommerfeld has demonstrated that it is legal to use spherical trigonometry in solving relative velocity compositions. In this work,
https://en.wikisource.org/wiki/Translation:...
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What is the line of sight distance across the ocean? [closed]
I just watched an experiment where they had a laser at a height of 50 feet (15 metre) above sea level and were able to see it 23 miles (37 km) away at a receiver which was 20 feet (6 metre) above sea ...
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How to (partially) cross-divide 3D vectors? [migrated]
A useful technique for vector cross-product:
It is often stated that there is no way to 3D cross-divide vectors, which is true, with caveats.
If we know that $ \vec{A} \times \vec{B} = \vec{C} $, and ...
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If we want to apply the formula for torque $= pE\sin\theta$. It is given in the problem that theta~0° [closed]
Why do we take sin theta to be theta only and not as sin0° ie., 0?
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Position of a particle in the plane [closed]
I'm here to ask a really stupid question just to be sure of its answer. My professor gave us an exercise where we have to determine the Lagrangian of a system that is formed by a circular ring of mass ...
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Conception of earth's size based on the width of the observable horizon when standing at sea level and the circumference of the earth
As an aid to conceiving of the size of the earth, using the information that the horizontal (left to right or right to left) width of (not the distance to) the observable horizon when standing at sea ...
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Discovery of a Formula for Geostationary Orbit Distance: Seeking Expert Feedback [closed]
I’m an amateur enthusiast without a formal academic background in mathematics or science. Recently, I stumbled upon an idea and derived a formula that I believe calculates the distance traveled along ...
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Throwing a ball in the air
When we throw a ball in the air, we know that if we do not throw it too high, then g can be held constant over the trajectory and we can approximate the curve by a parabola. However we also know that ...
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Einstein's notion of "covariant"
In his The Meaning of Relativity, pg. $11-12$, Einstein explains the notion of "covariant" along the following lines:
Consider a point $\mathbf x$ on a straight line $\mathbf x -\mathbf A=\...
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Potential of circle and $n$-gon
Consider power central fields $f \sim r^k, - \infty < k < \infty$,
and unit circle, "charged" in the sense of the field.
We will be interested in the potential within the circle,
i.e. ...
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Why does moment of inertia stop at 1/2 as solidness of a cylinder increases?
So I have two things about moment of inertia:
The I for a hoop is $I=MR^2$ and
the I for a solid disk is $I=\frac{1}{2}MR^2$
I've noticed that as "solidness" goes up from 0% (completely ...
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Finding Exterior Confining Pressure from Interior Pressure Point for a Solid Disk
Essentially, I've been wrapping the pictured object tightly with string to exert a confinement pressure on its exterior. It's been difficult however to make a good estimate of how much pressure is ...
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Is obeying the parallelogram law of vector addition sufficient to make a physical quantity qualify as a vector?
I know that obeying the parallelogram rule of vector addition is a necessary condition for vectors. But is it sufficient? In other words, can there be a quantity that is added using the method but ...
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Why are spherical shapes so common in the universe?
I have a simple question. Why are most objects in the observable universe spherical in shape? Why not conical, cubical, cuboidal for instance? I am furnishing a few points to justify this statement:
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