due at 11:59pm please help

Which of the items shown in the photo were developed using engineering design processes to develop a solution to a problem?

A. computer
B. coffee cup
C. table
D. pen

An engineer proposes that a newly developed chemical could be sprayed from aircraft to slow the rate of burning in a forest fire. What is the next step the engineer is likely to take to develop a solution to fighting forest fires?

A. test a number of similar chemicals

B. spray and compare the effectiveness of each tested chemical to water.

C. add the chemical to all aircraft spray tanks.

D. design a spray system for the chemical.

Answer:

Explanation:

I think I will say it is because most, if not all resistors have been made to standard already.

The value for the resistor that is chosen for two fixed arms from the Wheatstone Bridge have to be quite bear each other, as much as possible. The arm that moves and the other that doesn't move, their resistance values are made to be quite close as well. This makes the resistance of the arm that moves to be set somewhere in the middle, and as a result, the measurements don't exceed beyond the resistance range of the arm that moves.

I hope you understand?

Answer:

Well there are a lot of delicious food in the philppines but my most favorite is the Lechon, Adobo, Sisig, Chicken Curry, Crispy pata and Sinigang

Answer:

A) A mustache

B) A beard

Explanation:

A respirator is a device which is worn over the face to aid breathing through the use of oxygen. Because the fit is won on the face a mustache, or beard would change the fit of the respirator of the face as this would make the respirator tighter in some cases while in others not fit at all.

Answer: D) All of the above!

Explanation:

Answer:

Mach number = 0.68168

The flow should be treated as compressible.

Explanation:

Given that:

The altitude of a commercial jet = 35000

The properties of air at that given altitude are as follows:

Pressure = 24.577 kPa

Temperature T = 50.78176° C

Temperature T = ( 50.78176 + 273 )K = 328.78176 K

[tex]\varphi = 0.38428 \ kg/m^3[/tex]

The velocity is also given as: 550 mph = 245.872 m/s

Therefore, the sonic velocity is firstly determined by using the formula:

[tex]a = \sqrt{ \vartheta \times R \times T\[/tex]

[tex]a = \sqrt{1.4 \times 287 \times 323.78176[/tex]

[tex]a = \sqrt{130095.5112[/tex]

a = 360.68755 m/s

Then, we can calculate the Mach number by using the expression:

[tex]{Mach \ number = \dfrac{V}{a}}[/tex]

[tex]Mach \ number = \dfrac{245.872}{360.68755}[/tex]

Mach number = 0.68168

b) Ideally, all flows are compressible because the Mach number is greater than 0.3, suppose the Mach number is lesser than 0.3, then it is incompressible.

Answer:

i believe tungsten is stronger than titanium !

Answer:

Option B: An MSDS

Explanation:

A dictionary is used to check up the meaning of general words and not for checking if a substance being used is hazardous. Option A is wrong.

MSDS means "Material Safety Data Sheet" and it contains documents with information that relates to occupational health & safety for checking various substances and products. Thus, option B is correct.

SAE stands for Society of Automotive Engineering and their standards pertain to mainly Automobiles. Thus option C is wrong.

EPA guidelines are mainly for checking facility and environmental health and safety compliance. Thus, option D is wrong.

Answer:Modulus of Elasticity (E)-------- A

Explanation:

The modulus of elasticity, Young's modulus E is a measure of a material's stiffness or resistance to being elastically deformed when stressed or due to tension According to  Hook's law the modulus of elasticity is defined as the ratio of the stress to the strain and defined as the slope of its stress-strain region  in the stress and strain graph.

--The stiffer a material, the higher the elastic modulus and vice versa for a less stiff material.

it can be calculated with this formulae

Young’s modulus equation is E = tensile stress/tensile strain

= (FL) / (A X change in L)

where F = applied force,

L = initial length,

A = square area,

E = Young’s modulus in Pascals (Pa).

Answer:

True

Explanation:

True - because different classification of steel beam have different yield strength.

The moment capacity for a steel beam is given by;

M = Mn / Ωₙ

where;

M - the maximum moment acting on the beam

Ωₙ - is the Safety Factor for Elements in Bending = 1.67

Mn - nominal moment of the steel, given as

[tex]M_n = Z_x *f_y[/tex]

where;

Zₓ - the Plastic Section Modulus in the x or strong axis.

[tex]f_y -[/tex] is the Yield Strength of the Steel (A36W, A46 W or A50W)

A36W = 36 ksi

A46 W = 46 ksi

A50W = 50 ksi

Thus, before you calculate the moment capacity for a steel beam, you have to determine the classification of beam, for the yield strength of the steel beam.

Answer:

The moment of inertia of the rotor is approximately [tex]1.105\times 10^{-6}[/tex] kilogram-square meters.

The rotor inertia may differ from these assumption due to differences in the shape of cross section.

Explanation:

We assume that rotor can be represented as a solid cylinder of radius [tex]r[/tex], length [tex]l[/tex], made of cooper ([tex]\rho = 8960\,\frac{kg}{m^{3}}[/tex]) and whose axis of rotation passes through its center of mass and is parallel to its cross section. By definition of Moment of Inertia and Theorem of Parallel Axes, the moment of inertia of the rotot is:

[tex]I = \frac{1}{4}\cdot \rho \cdot \left(\frac{\pi}{4} \right) \cdot R^{3}\cdot (3\cdot R^{2}+L^{2})[/tex]

[tex]I = \frac{\pi}{16}\cdot \rho \cdot R^{3}\cdot (3\cdot R^{2}+L^{2})[/tex] (Eq. 1)

Where:

[tex]\rho[/tex] - Density of copper, measured in kilograms per cubic meter.

[tex]R[/tex] - Radius of the rotor, measured in meters.

[tex]L[/tex] - Length of the rotor, measured in meters.

[tex]I[/tex] - Moment of inertia, measured in kilogram-square meters.

If we know that [tex]\rho = 8960\,\frac{kg}{m^{3}}[/tex], [tex]L = 25\times 10^{-3}\,m[/tex] and [tex]R = 8.98\times 10^{-3}\,m[/tex], the estimated moment of inertia of the rotor is:

[tex]I = \frac{\pi}{16}\cdot \left(8960\,\frac{kg}{m^{3}} \right)\cdot (8.98\times 10^{-3}\,m)^{3}\cdot [3\cdot (8.98\times 10^{-3}\,m)^{2}+(25\times 10^{-3}\,m)^{2}][/tex]

[tex]I \approx 1.105\times 10^{-6}\,kg\cdot m^{2}[/tex]

The moment of inertia of the rotor is approximately [tex]1.105\times 10^{-6}[/tex] kilogram-square meters.

From D'Alembert's Formula we know that net force of rigid bodies experimenting rotation equals the product of moment of inertia and angular acceleration. In this case, the purpose is minimizing moment of inertia and it is done by modifying the shape of the cross section so that rotor could be aerodynamically more efficient.

Answer:

The field strength needed is 0.625 T

Explanation:

Given;

angular frequency, ω = 400 rpm = (2π /60) x (400) = 41.893 rad/s

area of the rectangular coil, A =  L x B = 0.0611 x 0.05 = 0.003055 m²

number of tuns of the coil, N = 300 turns

peak emf = 24 V

The peak emf is given by;

emf₀ = NABω

B = (emf₀ ) / (NA ω)

B = (24) / (300 x 0.003055 x 41.893)

B = 0.625 T

Therefore, the field strength needed is 0.625 T

Answer:

a) According to the maximum-shear-stress failure theory, the static factor of safety of the shaft is 2.440.

b) According to the distortion-energy failure theory, the static factor of safety of the shaft is 2.816.

Explanation:

First, we need to determine the torque experimented by the shaft ([tex]T[/tex]), measured in kilonewton-meters, whose formula is described:

[tex]T = \frac{\dot W}{\omega}[/tex] (Eq. 1)

Where:

[tex]\dot W[/tex] - Power, measured in kilowatts.

[tex]\omega[/tex] - Angular velocity, measured in radians per second.

If we know that [tex]\dot W = 10\,kW[/tex] and [tex]\omega = 20.944\,\frac{rad}{s}[/tex], then the torque experimented by the shaft:

[tex]T = \frac{10\,kW}{20.944\,\frac{rad}{s} }[/tex]

[tex]T =0.478\,kN\cdot m[/tex]

Let consider that shaft has a circular form, such that shear stress is determined by the following formula:

[tex]\tau = \frac{16\cdot T}{\pi\cdot D^{3}}[/tex] (Eq. 2)

Where:

[tex]D[/tex] - Diameter of the shaft, measured in meters.

[tex]\tau[/tex] - Torsional shear stress, measured in kilopascals.

If we know that [tex]D = 0.03\,m[/tex] and [tex]T =0.478\,kN\cdot m[/tex], the torsional shear stress is:

[tex]\tau = \frac{16\cdot (0.478\,kN\cdot m)}{\pi\cdot (0.03\,m)^{3}}[/tex]

[tex]\tau \approx 90164.223\,kPa[/tex]

a) According to the maximum-shear-stress failure theory, we get that maximum shear stress limit is:

[tex]S_{ys} = 0.5\cdot S_{ut}[/tex] (Eq. 3)

Where:

[tex]S_{ys}[/tex] - Ultimate shear stress, measured in kilopascals.

[tex]S_{ut}[/tex] - Ultimate tensile stress, measured in kilopascals.

If we know that [tex]S_{ut} = 440\times 10^{3}\,kPa[/tex], the ultimate shear stress of the material is:

[tex]S_{ys} = 0.5\cdot (440\times 10^{3}\,kPa)[/tex]

[tex]S_{ys} = 220\times 10^{3}\,kPa[/tex]

Lastly, the static factor of safety of the shaft ([tex]n[/tex]), dimensionless, is:

[tex]n = \frac{S_{ys}}{\tau}[/tex] (Eq. 4)

If we know that [tex]S_{ys} = 220\times 10^{3}\,kPa[/tex] and [tex]\tau \approx 90164.223\,kPa[/tex], the static factor of safety of the shaft is:

[tex]n = \frac{220\times 10^{3}\,kPa}{90164.223\,kPa}[/tex]

[tex]n = 2.440[/tex]

According to the maximum-shear-stress failure theory, the static factor of safety of the shaft is 2.440.

b) According to the distortion-energy failure theory, we get that maximum shear stress limit is:

[tex]S_{ys} = 0.577\cdot S_{ut}[/tex] (Eq. 5)

If we know that [tex]S_{ut} = 440\times 10^{3}\,kPa[/tex], the ultimate shear stress of the material is:

[tex]S_{ys} = 0.577\cdot (440\times 10^{3}\,kPa)[/tex]

[tex]S_{ys} = 253.88\times 10^{3}\,kPa[/tex]

Lastly, the static factor of safety of the shaft is:

[tex]n = \frac{253.88\times 10^{3}\,kPa}{90164.223\,kPa}[/tex]

[tex]n = 2.816[/tex]

According to the distortion-energy failure theory, the static factor of safety of the shaft is 2.816.

Answer:

The answer is below

Explanation:

Given that:

x = 5 cm = 0.05 m, width (w) = 5 cm = 0.05 m, thickness (t) = 1 mm = 0.001 m, k = thermal conductivity = 200 W/mK, h = heat transfer coefficient = 22 W/m².K, Tb = base temperature = 40°C, T∞ = 20°C

[tex]m=\sqrt{ \frac{hp}{kA} }=\sqrt {\frac{22*(2*0.05+2*0.001)}{200*(0.05*0.001)}} =15\ m^{-1}\\\\\frac{T-T_{\infty}}{T_b-T_{\infty}} =e^{-mx}\\\\\frac{T-20}{40-20} =e^{-15*0.05}\\\\T-20=9.45\\\\T=29.45^oC\\\\The\ rate\ of\ heat\ loss\ is:\\\\\dot{Q}=\sqrt{hpkA}(T_b-T_{\infty})\\ \\\dot{Q}=\sqrt{22*(2*0.05+2*0.001)*200*0.05*0.001}*(40-20)\\\\\dot{Q}=3\ W[/tex]

Answer:

190$-200$

Explanation:

Answer:

Your mobile phone has more computing power than the computers used for the Apollo 11 moon landing.

Mobile phones have to “work harder” to get a signal if you are in a moving vehicle.

The first mobile phone was made in 1973.

The first mobile phones that went on sale in 1983 cost nearly $4,000 each.

In 2012 Apple sold 340,000 phones per day.

4 out of 10 Brits admit to snooping on their partners phone.

Out of the 53% of snoopers that found incriminating evidence on their partner’s phone, 5% went on to terminate their relationship.

Waterproof mobile phones came to market because Japanese youngsters like to use them in the shower.

Apparently mobile phones have 18 times more bacteria on them than toilet handles!

Phubbing describes the act of snubbing someone by using your mobile phone in their company.

In 2015 more people died from taking selfies than shark attacks.

Teenagers that use a phone more than 2 hours a day increase their risk of depression and anxiety.

Nomobophobia is severe anxiety caused by the thought or act of losing your phone or running out of battery.

Explanation:

Answer:

It only detects errors if an odd number of bit flips have occurred.

Explanation:

Parity is a measure of how even or odd a string of digits (for example, a string of binary units is).  It is obtained by calculating the value of all the bits. Parity is used in error detection. A parity error is detected when the parity and the odd number of bits are incorrectly propagated.

A problem commonly associated with the parity bits is that they can only detect an odd number of bit errors. This means that if a digit is corrupted in the even binary digits there would be an incorrect detection of errors.