# All Questions

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### Why is the direction of angle theta in circular motion towards and inwards? [duplicate]

(You can ignore text in the image if not understood , I have edited all of that here as well) Why is the direction of angle $\theta$ in circular motion towards and inwards of plane xy axis? I am not ...
15 views

### Is this alternate grounding practice practically implementable?

While grounding power sockets in modular prefabricated steel buildings (see Light Gauge Steel Frame Technology), can we just connect the ground wire to the steel frame of the building itself? as the ...
27 views

### How to cut a thick glass block at home?

Due to pandemic, there are a lot of machine shops closed and delays in getting something custom made. I was wondering how to cut a triangular glass prism (~5cm hypotenuse) in the middle so I have two ...
14 views

### Bosch K-Jetronic Fuel Injection

Why people always say K-Jetronic will not work with high performance high duration cams and because of this the K-Jetronic equipped engines will not be making lots of power. In Bruce Andersons book &...
28 views

### Can anyone help me with this problem of rpm of lathe? [closed]

Calculate the revolutions that you would place on the lathe knowing that we are going to turn a piece of mild steel, 110 mm in diameter, with a cobalt tool.
24 views

### Given 3 force measurements, what are estimated forces at other locations?

Given three unequal force measurements spaced equally 120 degrees apart on a circular plate at F_R, F_C, F_L, I need to calculate what the estimated force measurements would be if taken at positions ...
19 views

### Tempering 1095 steel

I have some laser-cut filing templates, about the size of a business card, made from 3mm-thick 1095 carbon steel. These parts will be used to guide a round metal file when filing odd shaped holes in ...
16 views

### 24 hr stand alone real time clock module/IC [closed]

Can you please suggest a suitable stand alone IC/module that outputs a pulse once every 24 hrs. I suspect there exist a complete module with battery, 32 kHz crystal and freq divider IC combined, but I ...
28 views

### Why Stirling engine not used as primary source to operate generator in thermal power plants?

I did some research and found out that in order to generate that amount of electricity( consider about 100MW) the size of the Stirling engine will be very big as compared to that of a steam turbine. ...
22 views

### Calculate the thrust of a fan

I'm having some difficulty with the following problem: The fan operating parameters are adjusted to reduce the constant negative pressure at the inlet ($p_\infty-\Delta p$) within a certain range of ...
16 views

### Is there any way to focus the mechanical vibration or stress of an object?

I am looking for a way to focus the vibration of a metal sheet at a specific point on that sheet so that other points vibrate less. Just like light and lens. Is there any way to focus the mechanical ...
29 views

### Why is the direction of angle theta in circular motion towards and inwards? [closed]

Why is the direction of angle $\theta$ in circular motion towards and inwards of plane xy axis? I am not getting this concept at all.As the angel theta is changing ; the arc length (s in diagram ) is ...
47 views

### What is the type of pavement defect and how to address the issue?

Attached image is from a very high water table and high salinity area. What is the type of pavement defect and how to address the issue?
41 views

### Effect of frequency resolution on the frequency spectrum of impulse force delivered by an electromagnetic shaker

this is a part of my parameter study for the experiment (a vibration analysis with a force impulse input). This specific part studies the frequency resolution effect on the spectrum. The input (i.e.: ...
38 views

### Least force required

Relying on my past knowledge on how to attack the problem, I should use the equation Moment of B about AC = $r_{AB} \times B • n^ AC$ To find the least force on B. I just don't know what position ...
24 views

### Ramp up during build phase of oil production [closed]

Why is it important to ramp up during the build phase of oil production?
28 views

### Phasor representation of RC circuit

I am struggling to understand how to take the KCL equation from time domain to Phasor domain. The time domain KCL equation is easy to understand and represented here: The phasor domain equation looks ...
24 views

### Wireless communication modules transmitting through body

I wanted to be able to transmit data from a wireless module to an Arduino. It is possible that a human body could come between the wireless module and the Arduino or someone might cover up the module ...
22 views

### What really is the difference between allowable stress design and ultimate limit state design?

I'm trying to understand this difference. From what I've read, ASD basically deals with making sure the stress in a structure does not exceed a certain limit, the yield stress of the material. It ...
15 views

### How to solve this question relating to string [closed]

There are two string of mass 100g and a inextensible string(0g).length of string is 1m. There is load of 100kg. Where should the load be placed so that the string breaks in the minimum amount time ...
16 views

### Do we mean the normal reaction caused between the water and block [closed]

By resultant B of the contact force , do we mean the normal reaction caused between the water and block in this theory part section.
42 views

### Multiturn rotational limit switches

I would like to automate a door lock. For reasons I won't get into, I'm not allowed to modify the lock itself, I can only attach things to the "safe side" of the door. On this safe side, ...
648 views

### Unknown circuit component with glass encapsulated contacts

This is an unsoldered circuit component that had two metal pieces that weren't making contact inside a thin glass tube. What is this? I haven't seen anything like it before.
30 views

### Heat rate through composite wall with non-constant thermal conductivity

I just started a job working with cryogenics and I am trying to solve an interesting heat conduction problem that I was hoping someone could help me along with. I have a structure that spans from room ...
28 views

### Finding the reaction force at the hinge

The question given is A uniform rod, of mass $m$ and length $2a$ smoothly hinged to a vertical wall is connected to a point on the wall above the hinge by a light inelastic string. Find the magnitude ...
22 views

### Meaning of this sentence in lecture notes about buckling of nonlinear column

Above picture is from my lecture notes. It deals with a column subject to axial load, which follows Euler buckling theory. The material is nonlinear, approximated by two lines as seen in the stress-...
120 views

### Why is the direction of pressure always perpendicular to surface area for fluids?

Why is the direction of pressure always perpendicular to surface area of a body for fluids ? We also assume that it is an ideal fluid here. So , pressure acts in all directions because fluid has a ...
25 views

### Constructing small Kretschmann Surface plasmon set up

I am trying to build a SPR setup at home which is based off this diagram: I wanted to try to miniaturize it and had some concerns about my strategy. So I was thinking I could buy a big prism and ...
13 views

### Finding all the pressure acting on base of cylidner

Water is filled in a flask up to a height of 20 cm. The bottom of the flask is circular with radius 10 cm. If the atmospheric pressure is $1.013 \times 10^5$ Pa,find total force exerted on the bottom ...
18 views

### Why is the atmospheric pressure given as the value of length of mercury column in barometer

Why is the atmospheric pressure given as the value of length of mercury column in barometer. Since the density for the both the cases are different. Is it that by experiment we found the value to be ...
9 views

I am trying to solve problems on radix-4 (DIT & DIF) numerically. Unlike radix-2, when N = 8, and the values of x = {1,-1,0,2,1,-2,-1,0}, where n = 0,1,..., N/2 - 1. This, I can solve without ...
20 views

### Why are the two acceleration considered as a1 and a2 here and find acceleration of 6kg mass?

Why are the two acceleration considered as a1 and a2 here? What is the reason for this even though the tension of both the strings are same. T is equal to 5gTcos 53 for left side and 5gTcos37 for the ...
17 views

### RLC circuit problem

After the switch is open for a long time, it is closed at t = 0. How can I find iL(t) and Vc(t) for t>=0? I tried step response for RLC circuit but I could not apply.
18 views

### Energy content of confined fluids at same temperature [closed]

Two containers contain water at the same temperature. One of the two containers is twice as voluminous as the other. This container therefore contains twice as much energy as the other. False or True.
20 views

### Statically determinate system

he exercise is taken from linear algebra and its applications, prof. G.strang exercise 2.4.8 truss I have already found that: m=n=8 → system is statically determinate, therefore solvable by ...
54 views

### What thickness do I need for a 30x30 (cm) aluminium plate to hold 350Kg on three points?

I want to make a strong connected weight-scale Arduino project, for which I already own 3×350Kg sensors (red). I plan to make the plate (green) around 30cm×30cm in 99.5 Brut aluminum, with my three ...
11 views

### Fasten adjustable perpendicular cylinders rotating on axis

What part(s) make it simple to secure two perpendicular cylinders together when one of the cylinders is rotating on its axis? In the drawing below, C(3) rotates with a simple motor. C(1) and C(2) ...
21 views

### How can i create a RL circuit?

I want to create a RL circuit that has a dc voltage source, lamp, switch, R and L elements are connected in series.How can I design the circuit so that the lamp flashes from the moment the switch is ...
117 views

### Derive a formula for the propulsion force - verification request

I'm having some difficulty with the following problem: Derive a formula for the propulsion force containing $\rho, Q,S, u$ (pic below) The propeller is moving left with the speed u. My only idea was ...
66 views

### PID controller - Counterproductive derivative

I'm having trouble understanding the derivative part of a PID controller, because it sometimes seems to react the opposite way that I would like. Let's use a simple example where : the controlled ...
12 views

### Steel floor for a paint booth

I am attempting to cover an old half pit in a service station and convert the space into a paint booth. If i put a grid of 2ft x 4ft under the steel, how thick of sheet steel would I need to support ...
28 views

### Calculating how big a base to attach to a chair to prevent it toppling

I have a pair of cinema seats that are designed to be bolted to the floor. I don't want to do this so instead I have made wooden feet and bolted the seat to them and they are quite stable. I know ...
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### Assumption of specific enthalpy

Given an adiabat turbine with state 1 fluid data as: $$h_1 = a$$ $$p_1 = b$$ $$t_1 = c$$ and state 2 data fluid data as: $$h_2 = unknown$$ $$p_2 = e << b$$ $$t_2 = f < c$$ $$h_2' = g$$ h_2''...
10 views

### Number of layers required for composite mold

I am new to manufacturing and especially to composites. I have a cylinder to be made out of carbon fiber (only the outer shell) and I know the weight I want from this structure after manufacturing. Is ...
30 views

### What is the white fiber in the copper wire of headphones?

I got a pair of in-ear headphones, broke the left earphone, bought another set, broke the right earphone, and joined the leftovers of both. I found white, grey, or beige fibers near the copper of the ...
20 views

### Is a differential gear setup equivalent to a voltage divider?

I was wondering if a differential gear setup works equivalently to a voltage divider in the electric domain. As far as I understand, voltage is analogous to torque in mechanical engineering and ...
11 views

### Black powder detonation analysis in ANSYS

I have an Aluminium tube that I want to insert some black powder in it and explode. This will be used as a ejection system for a high altitude rocket. It will deploy two bodies or nose cone of the ...
30 views

### why we consider average current for dc while rms for ac in finding efficiency of half wave rectifier?

Efficiency= DC power output/Ac power input. DC power= I²(av.)*R. why average current? AC power= I²(RMS)*R. Why RMS current and not average this time?