# All Questions

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### How to accurately measure mass flow through server vents using an anemometer

I have to work out the air mass flow coming out each vent on a server and have proposed to use a hot wire anemometer to measure the air velocity at each vent by placing it slightly inside one outlets ...
935 views

### Driving many parallel shafts from one motor

Is there a preferred solution to the problem of driving parallel rotary shafts from a single motor? I have six shafts that I want to drive from one motor. The shafts are all: rotating the same ...
326 views

### How to calculate scarf ratio or lap overlap for composites?

I'm building a plane, and one of the solutions I've thought of for connecting the wing spars to the fuselage involves connecting carbon fiber parts. As mentioned in this answer, I found this ...
1k views

### How do I calculate the temperature change inside a box with a heat source? What if I ventilate the box?

I have a box (as shown below). I know the temperature outside of the box (for example you could use 293K) and I would assume the temperature inside the box is initially the same as outside of the box. ...
156 views

### Looking for a formula that states the stiffness of a composite [closed]

I am looking for a formula that states the breaking point of a composite - How much pressure it can withstand before it 'snaps'. Specifically I am looking for a formula that states the materials ...
208 views

### How to calculate monosymmetry index of an unequal angle? [closed]

I saw some formula involving integration. Is there a straightforward formula to calculate this instead given b, d, t and alpha angle between x-x and u-u axis?
248 views

### Shear Stress Formula

Could anyone tell me what the variables in this formula are? $$\tau=\frac{S\;a\; \bar{v}}{I\; t}$$ I believe it is used for shear stress and that $I$ is moment of inertia but unsure on the other ...
137 views

### How to determine heat exchanger equation?

What is the equation to determine the inside surface temperature along the length of the counter flow heat exchanger?
1k views

### Conjugate beam (M/EI)

I dont understand how the diagram of M/EI of conjugate beam drawn , can someone explain about it ? According to conjugate beam theorem , i know that the M/EI represent the w(x) , which is force per ...
81 views

### qualitative influence line of pinned support

For the highlighted part , why we need to replace the support at A with a roller guide ? We could see at A , it's a pinned support , right ? Pinned support will resist horizontal and vertical ...
1k views

### How to calculate deflection of a cantilever beam subject to point loading

I am trying to solve the following beam deflection problem: The cantilever beam is subjected to the point load at C. Generate the equation for the elastic curve by using the double ...
63 views

### How can I build a electronically controlled valve for a 1/4 inch tube

I'm looking for a practical efficient way to open and close a 1/4 inch gravity fed hose. Initially I was thinking of using a Solenoid, but can't find anything suitable. My second thought was using a ...
305 views

### Is continuous beam design deemed “unsafe” by any code of practice/design practice for reinforced concrete building structures?

I am asking this because some of my engineer friends said that they won't want to analyze beam as continuous beam for RC building structures, because it is "unsafe" to do so, whether it has anything ...
762 views

### Does the turbo-compressor increase the efficiency of car engine?

Once the turbo is on, more air can participate to the combustion, which also requires more fuel. Then, it's clear that the turbo can give more power (at the price of more consumption). Question 1: ...
967 views

### Pacejka Formula - natural values

For my racing game I am using a simplified Pacejka Magical Formula: $\mu_{lateral} = \mu_{0} * \mu_{1} * D * \sin(C * \arctan(B * x - E * (B * x - \arctan(B * x))))$ Where: $\mu_{lateral}$ is ...
2k views

### Sizing plate washers for through-bolting to concrete

We are working on some equipment that is going to be attached to existing, 3,000 psi reinforced concrete floor slabs. In some locations, the best way to do this is to through-bolt and 'sandwich' the ...
1k views

### How does Hysteresis in tires helps create friction?

I am currently reading “Fundamentals Of Vehicle Dynamics” by Thomas D. Gillespie. The author states how tires generate the required frictional forces for movement by 2 methods : 1)Hysteresis 2)...
47 views

### What changes can be made to a whistle to change these variables? [closed]

I have read that the longer the whistle the lower the pitch and the shorter the whistle the higher the pitch. But there are other factors. Pressure, size of the inlet, size of the outlet, diameter of ...
591 views

22 views

### Importance of equilibrium and compatibility equations in elasticity

What is the importance and relevance of equilibrium and compatibility equations in elasticity. What problem do they solve?
302 views

### Is battery-charge-stop-at-XX-percent circuitry not cheap? [closed]

I'm curious why IBM/Lenovo ThinkPad line is basically the only manufacturer/brand of mobility devices that includes circuitry and software that allows one to vastly prolong battery life of laptops ...
241 views

### Strain Energy Problem

A bar of length L and of uniform cross-section area A and second moment of area 1 is subjected to pull P.If the young's modulus of elasticity of the bar material is E,the expression for strain energy ...
36 views

### How can I attach a rotary encoder to a retractable string/wire? [duplicate]

I need to know how I can attach a rotary encoder to something string/wire that I can pull and it retracts automatically My idea was to take apart a retractable dog lead leash and affix it to it ...
70 views

### What signals are expected on the connectors for this 12V Volkswagen Scirroco wiper motor circuit

EDIT: added a picture of a very similar unit. I picked up a used VW rear? wiper motor that I want to use for a simple motion experiment. Having no idea how to power the thing I popped open the case ...
40 views

### Are there any turborotonde / turboplein designs with more than four exits?

For an at-grade intersection of multi-lane roads, the "Turborotonde" (Dutch language Wikipedia article) or "Turboplein" (Dutch language wegenwiki article) is an alternative to the multi-lane ...
1k views

### What is the reason for a reduction in entropy in a compressor

I was under the impression that the entropy reduction in a system only works with either mass or heat transfer. While I was researching intercooling of compressors I stumbled across a peculiar ...
185 views

### Thick walled cylinder theory - Stress/strain in ballooned out tube

I want to work out how much I can expand a piece of rubber tubing before it ruptures. The wall is 0.75mm and the ID 5mm. Hence I am working out the stress/strain from thick-walled cylinder theory ...