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1500 questions
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votes
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Do yielded columns buckle?
A sufficiently slender column will fail under compression below yield stress by bowing, releasing it's axial elastic strain. This is called buckling. Depending on the slenderness of the column, the buckling may be fully elastic, or may involve some…
4
votes
2 answers
Why does light bend after travelling half of the lens?
As light enters a denser medium from a rarer medium, it bends towards the normal. Why does the light bend after passing through point F & not E?
S.M.T
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What is the purpose of dead coils in the middle of a compression spring?
What purpose do dead coils in the middle of a spring serve? For example, this spring from a ballpoint pen has two dead coils at each end and two in the center of the spring. Why add dead coils in the middle? What advantage does this create, or what…
CBRF23
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4
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Why shouldn't we use Bernoulli beam theory if deformations and rotations are large?
I was going through the basic assumptions made by Bernoulli beam theory. I realized that one of the most important assumption in this theory is that the deformations and rotations of the beams are supposed to be small, not large. I couldn't…
Rameez Ul Haq
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4
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How to determine the dynamic response of a spring-mass system?
The Problem
I have the following system for which I would like to determine its dynamic response, taken from these lecture notes pg.20:
where the forcing functions are $u_1 = 1-U(t - t_0)$, $u_2=0$, and $u_3=0$, $U(\cdot)$ is the unit step function…
kostas1335
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4
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2 answers
How do I manufacture a fillet?
What are the most popular and the most efficient ways to machine a fillet on an external edge of an object? If I were to use a CNC mill, what tools can I use for it, and how would the method change with the radius of the fillet?
I could imagine that…
Slovakov
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4
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Equivalent viscous damper for friction damping
I have a friction damping system which is exited by a harmonic force FE (depicted on the left side).
Is there a way to convert the friction damper to a linear or nonlinear damper, such that the damping at a given excitement frequency is equal?
I am…
M. Martin
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4
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Amp-Hours vs Volts in electric chainsaw specifications
Can someone please explain what I am losing/gaining in the trade-off between Volts and Amp-Hours when buying a piece of equipment such as a chainsaw.
I'm currently comparing two items. I'm making this concrete with actual products because I think…
Guy
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4
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2 answers
Is sensor measurement uncertainty the same with its calibrator?
I'm trying to calibrate a proximity sensor A with another proximity sensor B. Say sensor B uncertainty is already known from the data sheet. However, for sensor A the uncertainty is nowhere to be found.
So I try to calibrate sensor A with the…
el-cheapo
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4
votes
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Flattening teflon plate
I have a 6" x 6" x 1/4" piece of carbon filled teflon that is slightly curved (I think it must have come off an roll of enormous diameter) that I need to flatten. The carbon fill is carbon black, not carbon fiber, in order to make the material…
DKNguyen
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4
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2 answers
Ensuring even flow in liquid pumping in distribution circuit under suction
I have a liquid circuit which looks a bit like that:
The system is under suction, and the flow rate through each unit should be about 10ml/min. However, we noticed that unit n and the ones the furthest away from the pump and bottle were not getting…
am304
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4
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2 answers
Why/when do we use a transition fit?
I'm self-learning a bit about preferred fits and tolerances and was wondering why transition fits were even a thing.
Clearance fits I understand, applications where you don't want parts to touch and "clear" each other.
Interference fits are for…
TwoWaySpeedOfLight
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4
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3 answers
Improving ac efficiency in car
I live in Oklahoma. HOT in summer.
I drive a small car. Honda Fit.
Seems to me, a smaller cabin would cool faster than a larger one.
If I "made my car cabin smaller," would the ac work better?
I was thinking empty pop bottles, but figure need to…
Rob Dye
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4
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3 answers
Is there a maximum life for things made out of stainless steel or cast iron?
Do steel objects have a maximum lifespan? I read that "316 stainless steel is estimated to last for 1200 years in a “rule“ environment before heavy pitting. In the marine environment this is reduced to a mere 260 years." Are they referring to steel…
Justify
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4
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3 answers
How does my automatic car shift without complete temporary loss of acceleration
When my car shifts gears, the car's acceleration never goes to 0. I feel that there is constant torque to the wheels throughout the entire shift.
How is this possible during a gear change?
Transmission is Ford's 10R80
Ardalan G.
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