Answer:
The answer is '[tex]2.9584 \ \frac{lbf}{ft^2}[/tex]'
Explanation:
Given:
[tex]\mu=3.96 \times 10^{-7} \ \frac{lbfs}{ ft^2}\\\\\gamma=0.0709 \ \frac{lfb}{ft^3}\\\\v= 1.8 \times 10^{-4} \ \frac{ft^2}{s}[/tex]
energy balance equation:
[tex]\ P_1 - P_2 = \rho gh_{L}[/tex]
[tex]V= \frac{\ Q}{ A}\\\\V= \frac{\frac{5000}{60}}{2 \times \frac{9}{12}}\\\\V= 55.55 \frac{ft}{s}[/tex]
calculating [tex]D_h[/tex]:
[tex]D_h= \frac{4 \times \ scetor \ area }{ wetted \ permetor}\\\\D_h=\frac{4 \times 2 \times \frac{9}{12}}{2(2+\frac{9}{12})}\\\\D_h= 1.0909 ft\\\\[/tex]
calculating [tex]R_e[/tex]:
[tex]R_e=\frac{VD_h}{V}\\\\R_e=\frac{55.55 \times 1.0909}{1.8 \times 10^{-4}}\\\\R_e=3.366 \times 10^5\\\\[/tex]
calculating relative vovghness:
[tex]\frac{k_s}{D_h}= \frac{\frac{0.006}{12}}{1.0909}\\\\[/tex]
= 0.0006875
If [tex]R_e= 3.366 \times 10^5 \ and \ \ \frac{K_s}{D_h} = 0.0006875 \ \ \ so, \ \ f= 0.019[/tex]
Calculating [tex]H_f[/tex]:
[tex]H_f= \frac{f \ l\ v^2}{ 2 \ g \ D_h}\\\\[/tex]
[tex]=\frac{0.019 \times 50 \times 55.55^2}{2\times 32.2\times 1.0909}\\\\= 41.727 \ ft[/tex]
Calculating pressure drop:
[tex]P_1-P_2= \gamma h_{L}\\\\[/tex]
[tex]= 0.0709 \times 41.727\\\\= 2.9584 \ \frac{lbf}{ft^2}[/tex]
A prototype boat is 30 meters long and is designed to cruise at 9 m/s. Its drag is to be simulated by a 0.5-meter-long model pulled in a tow tank. For Froude scaling find a)-The tow speed b)-The ratio of model to prototype drag c)-The ratio of model to prototype power.
Answer:
a) 1.16 m/s
b) 1/216000
c) (√15)/6480000
Explanation:
The parameters given are;
Length of boat prototype, lp = 30 m
Speed of boat prototype = 9 m/s
Length of boat model, lm= 0.5 m
a) lm/lp = 0.5/30 = 1/60 = ∝
(vm/vp) = ∝^(1/2) = √∝ = (1/60)^(1/2)
vm = 9 × (1/60)^(1/2) = 1.16 m/s
b) The ratio of the model to prototype drag, Fm/Fp, is given as follows;
Fm/Fp = (vm/vp)²×(lm/lp)² = ∝³
Fm/Fp = (1/60)³ = 1/216000
c) The ratio of the model to prototype power pm/p[tex]_p[/tex] = (Fm/Fp) × (vm/vp) = ∝³×√∝
The ratio of the model to prototype power pm/p[tex]_p[/tex] = √(1/60) × (1/60)³
pm/p[tex]_p[/tex] = √(1/60) × (1/60)³ = (√15)/6480000
A piston-cylinder device contains 0.1 kg of hydrogen gas (PG model: cv=10.18, k = 1.4, R= 4.12 kJ/kg-K) at 1000 kPa and 300 K. The gas undergoes an expansion process and the final conditions are 500 kPa, 270 K. If 10 kJ of heat is transferred into the gas from the surroundings at 300 K, determine (a) the boundary work (Wb), and (b) the entropy generated (Sgen) during the process
Answer:
(a) 151.84 kJ
(b) 2.922 kJ/K
Explanation:
(a) The parameters given are;
Mass of hydrogen gas, H₂ = 0.1 kg = 100 g
Molar mass of H₂ = 2.016 g/mol
Number of moles of H₂ = 100/2.016 = 49.6 moles
V₁ = mRT/P = 0.1×4.12×300/1000 = 0.1236 m³
P₁/P₂ = (V₂/V₁)^k
V₂ = (P₁/P₂)^(1/k)×V₁ =0.1236 × (1000/500)^(1/1.4) = 0.3262 m³
Boundary work done = (V₂ - V₁)(P₂ + P₁)/2 = (0.3262 - 0.1236)*(500 + 1000)/2 = 151.84 kJ
(b) Entropy generated ΔS = Cv · ㏑(T₂/T₁) + R ·㏑(v₂/v₁)
=10.18 × ㏑(270/300) + 4.12 ·㏑(0.3262/0.1236) = 2.922 kJ/K.
Which statement about tensile stress is true? A. Forces that act perpendicular to the surface and pull an object apart exert a tensile stress on the object. B. Forces that act perpendicular to the surface and squeeze an object exert a tensile stress on the object. C. Forces that act parallel to the surface exert a tensile stress on the object. D. Forces that decrease the length of the material exert a tensile stress on the object.
Answer:
A. Forces that act perpendicular to the surface and pull an object apart exert a tensile stress on the object.
Explanation:
Tensile stress is referred as a deforming force, in which force acts perpendicular to the surface and pull an object apart, attempting to elongate it.
The tensile stress is a type of normal stress, in which a perpendicular force creates the stress to an object’s surface.
Hence, the correct option is "A."
Answer:
The correct answer is A. Forces that act perpendicular to the surface and pull an object apart exert a tensile stress on the object.
Explanation:
I got it right on the Plato test.
Describe how you could achieve a high quality finish on your work
Answer:
efort
Explanation:
try your hardest
An example of matching and converting would be finding a new market in which to see a product, such as online or internationally.
True
False
Answer:
True
Explanation:
Matching involves putting compatible strength and opportunities together to acquire comparative advantage over the competition
Converting involves the transformation of perceived prospects or threats and weakness or lack of capacity into a chance or opening and strength
Therefore, since finding a new market in which to see a product such as online or internationally can help match the strength of the searcher to the opportunities available internationally and convert weaknesses finding a new market is an example of matching and converting
Explain working mechanism of safety valve.
Answer:
Safety valves are part of the safety features placed in the system to prevent the system from experiencing over pressures
Explanation:
A safety valve is a valve that is actuated automatically when the pressure on the inlet portion rises to a specified value to allow the outflow or discharge of fluid such as liquid, steam or gas out of the system to prevent the system pressure limit from being exceeded. The design of safety valves is such that the valve closes the emergency outlet port again once the system pressure returns to normal.
The new Boeing 777 aircraft was designed and engineered by a group of Boeing employees from manufacturing, marketing, and engineering departments and by representatives of Boeing’s customers (major airlines such as United and American Airlines), all working closely together in an intensive effort. This design and engineering group for the 777 can be classified as_________.
Answer:
A cross-functional team
Explanation:
A cross-functional team are a customer centric collection of professionals with diverse area of expertise that come together to attain a common purpose by collaboration which aids in the maximization of effort, investment, and time in achieving customer satisfaction and the goals of the organization
The team can comprise members from different departments within the organization such as marketing, finance, safety and quality, human resources as well as operations.
A widebody aircraft
The Boeing 777 is accounted as a wide body aircraft because it has 2 isles and other aircraft have one like the Boeing 737 is not considered as widebody because it has only one isle and like the Airbus A330-900 is a competitor to the Boeing 777 and has 2 isles in the aircraft so it is considered a wide body aircraft.
Determine size of a standard square key made of 1045 hot rolled steel for a 2 inch DIA shaft transmitting 100 HP at 500 rpm with factor of safety 2.5 for yield in direct shear. W____inch L_____inch
Answer:
Width = Length = 1.148 inches
Explanation:
We have been given the following data:
D = diameter = 2 inch = 0.0508m
P = Power = 100 HP = 74570 W
N = 500 rpm
Safety Factor = 2.5
Step 1:
We need to find yield strength which is represented by σ(y).
σ(y) for 1045 hot rolled steel = 330MPa
Step 2:Find Shear Strength. Formula is given:
τ(y) = σ(y) / 2
τ(y) = 330 / 2
τ(y) = 165 MPa
τ(y) = 165 × 10⁶ Pa
τ(y) = 165 × 10⁶ kg.m⁻¹.s⁻²
Step 3:
Find Torque. Formula is given:
T = 60P / 2πN
T= (60)(74570) / 2π(500)
T = 1424.9 Nm
Step 4:Find Shear Force. Formula is given:
F = 2T/d
F = 2(1424.9)/0.0508
F = 56098.43 N
F = 56098.43 kg.m.s⁻²
Step 5:Find length by the given formula:
F/L² = τ(y)/Safety factor
Rearrange for L:
L = √(F· Safety factor / τ(y))
Substitute the values found in previous steps to calculate L.
L = 0.02915 meters
Convert it into inches:
L = 1.148 in
As it si a square key:
L = W
Width = 1.148 in
Assignment
1. Study the design of roof in the building where you live. What type of roofing design is your building?
2. State the types of roofing materials that is used in the building where you live.
3. Give a screen shot of the roof of your house.
Answer:
pls I am sorry dis is not a reasonable question
Which material is used in a photovoltaic cell? A photovoltaic cell converts solar radiation into electric current using a thin sheet of____ like silicon.
Answer:
first on is silicon
Explanation:
Answer:
Silicon
Explanation:
Copper indium dieseline (CIS), cadmium telluride (CdTe), and thin-film silicon are certain polycrystalline thin film materials often used, whereas high-efficiency material such as gallium arsenide (GaAs) often comprise single-crystalline thin film materials3.