# All Questions

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57 views

### Why doesn't my wire follow ohm's law?

I have a 60mm length of wire with diameter of 0.5mm. Meaning it should have a resistance of 0.005 ohm. I put a constant voltage of 0.3volt through it, but it's only taking 7amp, but according to ohm'...
117 views

### Mechanical/electronic chalkboard cleaning device to replace the conventional duster to clean the chalkboard

The chalk board duster which is used by teachers to wipe the chalkboard seems very agonizing for them. What new mechanical/electronic devices can be devised to replace conventional chalkboard duster ...
20 views

### How to calculate the clock cycle in relation to bytes per clock bus?

In wikipedia there is the following With the speed of instruction fetch reduced by 50% in the 8088 as compared to the 8086, a sequence of fast instructions can quickly drain the four-byte prefetch ...
24 views

### What is the linear strain for given lateral strain?

So, I am trying to calculate the linear strain of a shaft which is under plastic deformation in yielding region. The diameter is changing from 2d to 1.5d I'm assuming that the volumetric strain is ...
33 views

### Calculating features of a 3 phase power timeseries

I have data from a number of high frequency data capture devices connected to generators on an electricity grid. These meters collect data in ~1 second "bursts" at ~1.25ms frequency, ie. ...
13 views

### Phase shift of transfer function using MATLAB

I'm trying to compute the phase shift of a transfer function (accelerance) in MATLAB, but I'm having issues. The transfer function was computed by dividing the magnitude of the system output by the ...
25 views

### Pipe Invert Elevation

Can someone please help and explain if the invert elevation of the pipe is calculated as 192+2+10? or 192+2+10+0.6667 (8" pipe)? Or 192+2+10+1 (measured to bottom)? Sketch is not to scale.
48 views

### Would this air amplifier attachment increase a leaf blower's effectiveness?

With the start of the leaf raking/blowing season just a month away, I have been thinking of a way in which I could make my old leaf blower more effective so I can spend less time doing leaf blowing. I ...
102 views

### Why Sony headset's charging station doesn't charge other NiMH batteries rather than which came with it?

I've got a Sony MDR-RF4000 wireless headset, which is already 7 years old, so obviously its NiMH battery (Sony BP-HP550-11, basically a pair of AAA NiMH rechargeable batteries tied together) shows the ...
44 views

### Block reduction need someone to check my work

I tried to solve this block but I am not sure if the end result is any good, some feedback would be nice.
108 views

### Is design of “Budweiser's bow-tie shaped beer can ” feasible & unique from engineering point of view?

Is design of "Budweiser's bow-tie shaped beer can " feasible & unique from engineering point of view? Can there be a better design than it? Like the shape of can is inclined at ten ...
25 views

### Hydrostatic Pressure in Soil

In a saturated soil, why is the pore water pressure equal to hydrostatic pressure? Terzaghi's principle states that the effective stress between solid particles is equal to the total stress $t$ minus ...
22 views

### Is there a material that returns to original, curled form when straightened?

Is there a material that 'wants' to be curled up but can be straightened an indefinite number of times without failing?
47 views

### What is pitch stability in cars?

Can reduction in pitching moment of a car be referred to as improved pitch stability? Or is this term strictly only with regards to aircrafts?
56 views

### Beam buckling criterion?

If I have an I beam which I subject to some bending load, how can I calculate when the thinner middle part of the I beam will buckle? I though I could use Euler's critical load formula here, but it's ...
38 views

### Calculate elastic modulus of titanium [closed]

I would like to work out the elastic modulus of a specific grade of titanium. Further to this I would like to learn how to calculate the maximum tensile strength of that metal in relation to its cross-...
31 views

### I need to find the direction of absolute velocity of B. B is going outwards the cylinder while rotating, so I can't find a way to do this

I found the abs. velocity of A as 0.4 m/s perpendicular to OA. It is saying that B is moving out of the cylinder at uniform velocity of 0.1 m/s, does that mean the abs. velocity of B is 0.4 + 0.1 = 0....
885 views

### How does a helicopter hover

I am wondering how a helicopter manages to stay balanced and stay in one spot while it is in the air. I understand that there is a second rotor that is used to counteract the angular momentum and also ...
21 views

### What is the best way to install vacuum insulation panels on house masonry walls?

What are the challenges that comes with installing VIP on a wall? Is installing the vip on the outside better than the inside?
59 views

### Are stuffing box still relevant?

Three problems: Internal friction due to stuffing materials. - Why does it not matter? If it does then there must be some limits like rpm etc. Not entirely leak proof. - Why are we supposed to keep ...
44 views

### Membrane permeate prediction software

I wanted to know if there are any open software or even purchasable software available to predict the permeate quality through a nanofiltration module. I am designing a plant for my final year ...
27 views

### How do I calculate the torque of a crank?

So, I have a crank that has a lever attached to a fulcrum, which rotates about an axis. But I also have a handle attached perpendicular to this lever, and the effort force is applied to the handle 90° ...
35 views

### Looking for specific bearing

I am new to mechanical engineering so I don't know the terms for different bearings. I'm trying to make a honey extractor. I have a rotating basket made out of stainless steel that is going a maximum ...
16 views

### Brick parapet material

Can someone please help. I'm trying to determine if stone or metal coping is preferred for brick parapet wall in terms of weather-ability.
25 views

### Wood Dimensional Stability

Between Glue Laminated and steel plate sandwiched between two wood beams, which one is more dimension-ally stable?
39 views

### What is the function of jumper pins on a 4 channel relay?

Attached is a picture of a 4 channel relay. I have searched the internet for the function of the jumpers circled in red. They are labelled Low Com and High. On all sites which I have looked at they ...
30 views

### What temperature required to alloy copper and aluminum?

According to this phase diagram, the melting point of 30% copper aluminum bronze is around 548°C. Lets say I create molten aluminum at 680°C, can I add small pellets of copper and swirl them around to ...
49 views

### Beam/column sizing

If a load P is applied as shown to a fixed column-beam, pinned at the bottom, should the beam or column (or both) sizes be increased to resist the load?
29 views

### Is it just surface area alone that causes bridges to freeze?

Scenario: Object 1, a bridge freezes over do to the surface area exposed to the below freezing air. Object 2 has the same surface area exposed to the same air, but its base sits on the ground that is ...
83 views

### What is “reversal” in mechanical engineering drawing?

I've come across these terms "reversals allowed" and "reversals not allowed" in a sample drawing while reading a GD&T course. What exactly are these terms? What do they mean?
35 views

### Question on the determinacy of frame structures

I have been working on a program to solve frame problems, and I have used the following formula for determining whether a frame is statically determinate: $$RD=3m + r-3j-s,$$ where: $m$ is the number ...
19 views

### Using complementary filter in rotation matrix

I am using accelerometer and gyroscope and try to compensate earth gravity. I figured out use of complementary filter, that calculates pitch and roll angle. On account of compensating gravity I am ...
26 views

### What are the disadvantages of fuzzy logic controllers when compared to MPC for robot/car control?

On the surface, fuzzy logic controllers seem like a good solution for something like robot control (steering, braking and acceleration), they can deal with uncertainties and non-linearities (for type ...
22 views

### Long term engine issues by using Active Exhaust?

Looking to install OEM active valve mufflers on my 2019 Mustang EcoBoost. Wondering if the valves opening and closing, thus changing exhaust back-pressure would cause the engine to run lean/rich and ...
40 views

### How do you maintain a constant pressure in a pipe with multiple outlets?

I've seen in piping and ventilation systems, when they branch off, the continuation of the main trunk gets smaller. Presumably this keeps the pressure (sorta) constant along the whole length of the ...
6 views

### Abaqus: How to properly retain nodes positions for models that undergoes two separate analysis (undamaged & damaged structures)

I'm not sure If I've worded the title correctly, but basically I have two steel bars, one that is undamaged (fully intact, model U), and another one is damaged (drilled a half pass through hole on the ...
59 views

### Setting up a radiation heat transfer problem

I am trying to solve a radiation heat transfer problem. The problem is set up like this: Two spherical shells of radius R whose surfaces are separated by a distance R. One shell, call it A, has a ...
33 views

### Wind turbine that is efficiant from all angles [closed]

What shape propeller with a large surface are, would be best propelled from the wind from behind and from the side as well as the front while facing the sun? I am thinking a pinwheel, but maybe there ...
56 views

### Limits of Euler-Bernoulli Beam Theory for Wide Plate in Flexure?

I'm looking for established limits or rules of thumb for the validity/accuracy of Euler-Bernoulli beam equations for particularly wide "beams". For example, a simply supported rectangular ...
27 views

### Rack and Pinion: Increasing Linear Movement of Rack

I would like to know if there's a way to increase the linear travel of a rack relative to the rotation of the driven shaft, either through a gearing system or some other means?
46 views

### What theories solve the problem of weight dispersion to minimize damage?

I assume there's some simple link to give me to answer this, but I don't know the terminology for it and so haven't been able to solve this. The use case it to avoid having my TV put divots into my ...
37 views

### Why do vibrations of a string create inharmonic noise past a certain amplitude of excitation?

When a real world string is plucked hard, like a guitar string, it enters a very brief period of noise generation after the release of the plectrum. Analysis of the output appears as pure chaotic ...
32 views

### determine if the flow is laminar or turbulent [closed]

what would be the the type of flow if the water flows through stainless steel channel? would it be a laminar flow or turbulent flow. I assume the adhesive force of water to stainless steel is minimum.
33 views

### Is it possible/practical to mold a single hollow piece of carbon fiber with a sealed vacuum in the middle?

Let's say I design a simple piece of carbon fiber to be manufactured, in the shape of a simple cylinder with a diameter of 2cm and a height of 3cm (pretty small). Is it possible and/or practical to ...
29 views

### Requesting a book that is an overview of chemical engineering [closed]

I am looking for an accessible chemical engineering overview within a book. Hi, please consider this question "generalizeable" so the question does not get deleted. But I will discuss my ...
26 views

### Does filter surface area affect resistance?

I am in the process of designing the enclosure for a small kiosk like project, and intend on having two fans (Noctua NF-A12x25, chosen for their high runtime rating, quietness, as well as other ...
39 views

### Crossflow HX tube and fin, derive Tout hot side as a function of mdot hot side in

Apparatus: Crossflow Tube and fin HX. (liquid-to-air Intercooler), Hot Side: Tube side, gas flowing internally Cold Side: fin side, water flowing in crossflow Goal: Generate an environment in "...
85 views

### Protection against accidents when chainsaw chain breaks

I've just bought myself an electrical chainsaw. Specifications of the chain velocity of my saw read 55 km/hr. I've read online that many wood-cutters have encountered chain breaks and want to protect ...
I have a sensor which detects wifi signals of nearby devices if their wifi mode is enabled. To process these data, I want to know if there is a specific time delta $\Delta t$ between each wifi hit. ...