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1500 questions
5
votes
1 answer
Sign convention in Mohr's circle
I don't really understand the explanation in the circled part of the image below (from here).
From the diagram, we can see that the shear stress that cause the element to turn clockwise is positive, but in the text there, the author stated that the…
kitzlong
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Why do bluetooth headsets get interference (choppy sound quality) outdoors?
This is more of a general physics question to help me understand how to choose sports headsets in the future, however it is too specific to a certain use case (bluetooth headset) to belong in the Physics StackExchange.
Problem:
3 of my 4 sports…
allanlaal
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5
votes
3 answers
Measuring the road surface quality
First of all, excuse my little knowledge, I'm a computer programmer by trade and unfortunately have very little knowledge of physics, engineering, DSP but I'm willing to learn.
I would like to measure the quality of a road surface when riding on it…
Johannes Weiss
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5
votes
2 answers
Anomalous oxygen in aluminium sample SEM EDS
I have a sample of aluminium which I'm interested in finding the rough composition of.
The sample is a part of a large number of samples which I sanded down and polished with a polishing table. I cleaned the samples with acetone, washed and rinsed…
Tapio
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5
votes
4 answers
How to simulate car acceleration
I am a high school physics student and I've been trying to simulate the acceleration of a car as it fully accelerates from rest, but I'm finding it's much harder than I thought. Here was my first attempt (without including air resistance):
I used…
Ryan
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5
votes
2 answers
How to obtain sensor failure probabilities?
I'm a computer science student doing research in wireless sensor networks (WSN) optimization. Based on past research works, sensors are capable of failing due to a number of factors such as harsh environmental conditions, communication errors, and…
user8621
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5
votes
1 answer
What are the predominant types of concrete pumps and what are their working mechanisms?
I've looked around for different types of concrete pumps and simply don't know if there are many different types, what their mechanisms are and which ones are the most predominant ones.
What I've found:
This video explains how a pump with an…
JHK
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5
votes
2 answers
What is the correct pipe size for a 2inch pipe?
I'm was looking into the ASME B16.5Pipe flanges and pipe fittings and it has 2 dimension tables metric and inches.
What I found was rather strange for me. I was looking at a 2 inch welding neck flange, and the hub diameter must match the pipe…
Mech_Engineer
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5
votes
3 answers
How to know which modes are excited by a given input in modal analysis?
Consider a simple structure such as a beam, plate, ... Assume that you know how to determine the different modes of vibration of the structure. You are given an external input, such as a force or moment at a certain location. How can you then…
Karlo
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5
votes
1 answer
How long can UK diesel be stored?
We have standby diesel generators that are only run a few times a year. How long can we reasonably keep the diesel stored on site before using or disposing of it?
It is accepted that there is a finite shelf life particularly after the UK has started…
dhewett
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5
votes
1 answer
Contradictory units for moments of inertia
I'm looking at a motor datasheet where the moment of inertia is specified in units of "oz in sec^2". I would think that inertia should have dimensions of mass * length^2.
I did some further Googling and found that some automatic unit conversion…
Max
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5
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0 answers
Fluid dynamics of non interacting tanks in series
I have a system like this:
and I have to estimate the height of the lower tank.
First of all, I'm considering that I have a non-viscous, incompressible fluid in steady flow.
Base apertures
The outlet velocity of liquid when draining a tank or a…
Unnamed
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5
votes
1 answer
Is there a difference between punching shear for columns on slabs vs slabs on columns?
Might there a difference in design approach for punching shear for the two scenarios? Or something to pay particular attention to?
Is the slope of the shear plane (normally 1:1) the same for both scenarios? I would assume that it is, since the two…
SlydeRule
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5
votes
3 answers
Do heat pipes work in any orientation?
I think I understand how heat pipes work, and thus the following one has me flummoxed:-
It's from a typical bulk order Chinese web site, but I've seem many similarly contorted arrangements. They are very common in the over clocking /modding…
Paul Uszak
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5
votes
2 answers
Improvements in ammunition design?
In a news article today the reporter claims that modern improvements in "ammunition design" have made long rife barrels unnecessary for assault weapons. Here is the paragraph:
The 20-inch barrel isn’t needed anymore.
One of the biggest differences…
Wallace Park
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