A vapor-compression refrigeration cycle operates at steady state with Refrigerant 134a as the working fluid. Saturated vapor enters the compressor at 2 bar, and saturated liquid exits the condenser at 8 bar. The isentropic compressor efficiency is 80%. The mass flow rate of refrigerant is 7 kg/min.
1-Write the assumptions no less than three
2-Draw clear Schematic
(3) the compressor power, in kW.
(4) the refrigeration capacity, in tons.
(5) the coefficient of performance.
Answers
Answer:
(3) the compressor power, in kW. = 4.17KW
(4) the refrigeration capacity, in tons.= 4.905tons
(5) the coefficient of performance. = 4.1336
check attached files for other answers.
Explanation:
Related Questions
A circular bar will be subjected to an axial force (P) of 2000 lbf. The bar will be made of material that has a strength (S) of 24 kpsi. After some calculation, the designer has selected a standard 1/2 in diameter (d) bar. The factor of safety (n) is ____. Round the answers to three significant digits.
Answers
Answer:
[tex]n = 2.36[/tex]
Explanation:
The stress experimented by the circular bar is:
[tex]\sigma = \left[\frac{2000\, lbf}{\frac{\pi}{4}\cdot (0.5\,in)^{2}}\right]\cdot \left(\frac{1\,kpsi}{1000\,psi} \right)[/tex]
[tex]\sigma = 10.186\,kpsi[/tex]
The safety factor is:
[tex]n = \frac{24\,kpsi}{10.186\,kpsi}[/tex]
[tex]n = 2.36[/tex]
The coupling is used to connect the two shafts together. Assuming that the shear stress in the bolts is uniform, determine the number of bolts necessary to make the maximum shear stress in the shaft equal to the shear stress in the bolts. Each bolt has a diameter dd. Express your answer in terms of some or all of the variables rrr, RRR, ddd, and TTT. nn
Answers
Answer:
n = 2r³/Rd²
Explanation:
See the attached file for the derivation.
The entire population of a given community is examined, and all who are judged to be free from bowel cancer are questioned extensively about their diets. These people then are followed for several years to see whether or not their eating habits will predict their risk of developing bowel cancer.
a. Cross-sectional study
b. Case-control study
c. Prospective cohort study
d. Historical prospective cohort study
e. Clinical trial
f. Community trial
Answers
Answer:
type of study design is Prospective cohort study
Explanation:
This study follows overtime in a group of similar people who differ from some of the factors in the study to determine how factors may affect the outcome rate. Tests may vary depending on the hypothesis given by Cretin patients who are cigarette patients, who are most likely to be smokers, then most likely to be over 20 years of age, with a high rate of lung cancer. The effective cause of the disease is determined by the method of screening of the individuals below.Diesel-fueled generators are frequently used as backup electrical power sources for homes and hospitals. Consider a Diesel powered generator with an efficiency of 39 percent for an engine speed of idle to about 1,800 rpm (revolutions per minute). If Diesel fuel has a chemical formula of C12H23.
a. Determine the chemical reaction for 1 kmol of Diesel fuel burning with the stoichiometric amount of air.
b. For each kg of Diesel fuel burned, how much CO2 is generated, in kg?
c. Find the higher heating value (HHV) for C12H23 at 25°C, 1 atm.
d. Calculate the amount of Diesel fuel, in kg and in gallons, required to produce a power output of 18 kW to a home for a period of 8 h.
e. Comment on your results.
Answers
Answer:
a. C12H23 + 84.5 moles of air —-> 12CO2(g)+ 11.5H2O(g)
b. 3.2kg of CO2 per 1kg of C12H23
c. HVV of C12H23 is -1724.5 KCal/mol
d. Total weight required is 30.742kg
e. The amount of CO2 produced per kg of C12H23 is too much. CO2 is harmful to the environment and should be produced in weights as low as possible
Explanation:
Please check attachment for complete solution and step by step explanation
The function below takes a single string parameter called sentence. Your function should return True if the sentence contains at least one copy of each of the following vowels: a, e, i, o, and u. Otherwise, return False. The vowels can be either upper case or lower case.
student.py
Bef contains_all_values (sentence): 1 w
Answers
The question asks for a function to check if a sentence contains all five vowels at least once, regardless of case sensitivity. A solution involves creating a set of vowels and comparing it to a set of found vowels in the sentence, returning true if all vowels are present.
Explanation:The question relates to determining whether a given sentence contains all five vowels (a, e, i, o, u) at least once, ignoring case sensitivity. This problem is typically solved using a function that iterates through each character in the sentence, checks if it is a vowel, and then keeps track of whether all vowels have been encountered. The essential steps involve converting the sentence to lowercase (to ignore case sensitivity), then checking for the presence of each vowel. A simple approach is to use a set to keep track of the vowels found, and once the set contains all five vowels, the function can return True. Otherwise, it returns False after checking the entire sentence.
An example implementation could be:
def contains_all_vowels(sentence):vowels = set('aeiou')
found = set(c.lower() for c in sentence if c.lower() in vowels)
return found == vowels
This code creates a set of vowels and then iterates over the sentence, adding each encountered vowel to another set. If, by the end of the sentence, the second set is equal to the set of all vowels, the function returns True; otherwise, it returns False.
Determine the nature of the following cycle (reversible, irreversible, or impossible): a refrigeration cycle draws heat from a cold reservoir at 250 K and rejects 950 KJ to a hot reservoir at 300 K while receiving 70 kJ of work to operate. Draw a schematic of the cycle clearly indicating the hot and cold reservoir and the direction of heat and work transfers. (10 pts.)
Answers
Answer:
Impossible.
Explanation:
The ideal Coefficient of Performance is:
[tex]COP_{i} = \frac{250\,K}{300\,K-250\,K}[/tex]
[tex]COP_{i} = 5[/tex]
The real Coefficient of Performance is:
[tex]COP_{r} = \frac{950\,kJ-70\,kJ}{70\,kJ}[/tex]
[tex]COP_{r} = 12.571[/tex]
Which leads to an absurds, since the real Coefficient of Performance must be equal to or lesser than ideal Coefficient of Performance. Then, the cycle is impossible, since it violates the Second Law of Thermodynamics.
In your new role at Wayne Industries, you have been given the freedom to propose and develop your own project ideas. You have an idea for a frictionless piston-cylinder assembly. Your design requires the expansion of 0.25 m3 of air at 3.3 MPa and 280 oC to 180 kPa in a slow, isothermal process. In order to be approved for further development, you need to submit calculations for the values of the heat transferred in the process.
Answers
Answer:
461.65 KJ/Kg
Explanation:
In this question, we are asked to calculate the values of heat transferred in the process.
Please check attachment for complete solution and step by step explanation
Boron fibers (of total mass 5kg, rho B = 2.3g/cc, σy B = 55MPa) are uniaxially introduced into 8kg of an Al matrix (rho Al = 2.7g/cc, σy Al = 10MPa). There is no porosity before and after composite fabrication. Calculate the density of the composite, yield strengths parallel and perpendicular to fiber orientations.
Answers
Answer:
Explanation:
Check attachment for step by step solution
Utilizing the charge neutrality equation and the mass-action law derive an expression for the concentration of electrons and holes present inside a p-type compensated semiconductor material. How can the resulting expression be modified for practical cases where (????????AA − ????????DD) ≫ 2nn�
Answers
Answer:
The expression for the concentration of electrons is P = NA - ND
Explanation:
Please look at the solution in the attached Word file
A piston-cylinder assembly contains 2 lb of air at a temperature of 540 °R and a pressure of 1 atm. The air compressed to a state where the temperature is 840 °R and the pressure is 6 atm. During the compression, there is a heat transfer from the air to the surroundings equal to 20 Btu.
1. Using the ideal gas model for air, determine the work during the process in Btu.
Answers
Answer:
123.9 Btu
Explanation:
The energy balance on the air is:
∆E = E2 − E1 = ∆KE + ∆PE + ∆U = Q + W
ignore ∆KE and ∆PE,
W = ∆U − Q = m(u2 − u1) − Q; (u2 − u1 = 51.94 Btu/lb)
ideal gas properties is attached
W = (2 lb)(143.98 − 92.04) Btu/lb − (− 20 Btu) = 123.9 Btu
u2 − u1 ≈ cv(T2 − T1) = (0.173 Btu/lb°R)(840 − 540) °R = 51.9 Btu/lb
The net work done in compressing the air as given is; W = -123.8 Btu
What is the Energy Balance equation?The equation for Energy Balance in thermodynamics is;
Q - W = ΔU
where;
Q is
ΔU is change in the internal energy of the system
Q is the net heat transfer
W is Net work done
Now, ΔU can also be written as;
ΔU = mC_v(T₂ - T₁)
C_v for air is 0.173 Btu/bm.R
We are given;
m = 2 lb
T₁ = 540 °R
T₂ = 840 °R
Q = -20 Btu (negative because heat is transferred to the surrounding)
Thus;
ΔU = 2 * 0.173 * (840 - 540)
ΔU = 103.8 Btu
Work done during the process is;
W = Q - ΔU
W = -20 - 103.8
W = -123.8 Btu
Read more about Energy Balance at; https://brainly.com/question/25329636
Five hundred gallons of 89-octane gasoline is obtained by mixing 87-octane gasoline with 92-octane gasoline. (a) Write a system of equations in which one equation represents the total amount of final mixture required and the other represents the amounts of 87- and 92-octane gasoline in the final mixture. Let x and y represent the numbers of gallons of 87- and 92-octane gasoline, respectively. (b) Use a graphing utility to graph the two equations in part (a) in the same viewing window. As the amount of 87-octane gasoline increases, how does the amount of 92-octane gasoline change? (c) How much of each type of gasoline is required to obtain the 500 gallons of 89-octane gasoline?
Answers
Explanation:
a) The total volume equals the sum of the volumes.
500 = x + y
The total octane amount equals the sum of the octane amounts.
89(500) = 87x + 92y
44500 = 87x + 92y
b) desmos.com/calculator/ekegkzllqx
As x increases, y decreases.
c) Use substitution or elimination to solve the system of equations.
44500 = 87x + 92(500−x)
44500 = 87x + 46000 − 92x
5x = 1500
x = 300
y = 200
The required volumes are 300 gallons of 87 gasoline and 200 gallons of 92 gasoline.
The brakes on a vehicle work OK for a while, then the vehicle slows because the brakes self- applied. Technician A says that an overfilled master cylinder could be the cause. Technician B says that a blocked vent port (compensating port) could be the cause. Which technician is correct?
A. Technician A only
B. Technician B only
C. Both technician A and B
D/ Neither technician A nor B
Answers
Answer:
C. Both technician A and B
Explanation:
If the master cylinder is overfilled it will not allow enough room for the brake fluid to expand due to heat expansion. This blocks the vent port. If a vent port is not open, brake fluid pressure will increase as brakes heat up. This will cause the brakes to self apply, cause more heat in the brake fluid and the vehicle will slow down.
There, we can conclude that Both technician A and B are correct.
Answer:
C. Both technician A and B
Explanation:
The event that made both cylinders to be over filled especially the master cylinder and the blocking of the vent port, this will cause the vehicle brake to apply itself after just a little motion of the vehicle.
Therefore both technicians are correct from the information given above.
Hence, we can boldly say the correct answer is C. ie Both technician A and B
thermodynamics A nuclear power plant based on the Rankine cycle operates with a boiling-water reactor to develop net cycle power of 3 MW. Steam exits the reactor core at 100 bar, 620°C and expands through the turbine to the condenser pressure of 1 bar. Saturated liquid exits the condenser and is pumped to the reactor pressure of 100 bar. Isentropic efficiencies of the turbine and pump are 87% and 78%, respectively. Cooling water enters the condenser at 15°C with a mass flow rate of 114.79 kg/s. Determine: (a) the percent thermal efficiency. (b) the temperature of the cooling water exiting the condenser, in °C.
Answers
Answer:
(a) the percent thermal efficiency is 27.94%
(b) the temperature of the cooling water exiting the condenser is 31.118°C
Explanation:
2.) For a 20‐mm‐diameter tube with either water or unused engine oil flowing through it, find: a.)The mean velocity, hydrodynamic entry length, and thermal entry length for each of the fluids with a temperature of 300 K if the mass flow rate is 0.01 kg/s. b.)The mass flow rate, hydrodynamic entry length, and thermal entry length for each fluid at 400 K and a mean velocity of 0.02 m/s.
Answers
Answer:
a.) The mean velocity = 0.0318 m/s
The hydrodynamic entry length = 0.636 m
The thermal entry length = 0.004 m
(b) The mass flow rate = 0.0051 kg/s
The hydrodynamic entry length = 0.028 m
The thermal entry length = 1.419 m
Explanation:
See the attached files for the calculation.
Specifically, the following methods must be implemented in the LinkedList class: (You should utilize listIterator() method already defined in the LinkedList class to obtain its LinkedListIterator object, and use the methods in the LinkedListIterator class to traverse from the first element to the last element of the linked list to define the following methods.)
Answers
Answer:
Attached to this solution is a Seventeen pages of code. Cheers!
Explanation:
A conical enlargement in a vertical pipeline is 5 ft long and enlarges the pipe diameter from 12 in. to 24 in. diameter. Calculate the magnitude and direction of the vertical force on this enlargement when 10 f t3/s of water flow upward through the line and the pressure at the smaller end of the enlargement is 30 psi.
Answers
Answer:
F_y = 151319.01N = 15.132 KN
Explanation:
From the linear momentum equation theory, since flow is steady, the y components would be;
-V1•ρ1•V1•A1 + V2•ρ2•V2•A2 = P1•A1 - P2•A2 - F_y
We are given;
Length; L = 5ft = 1.52.
Initial diameter;d1 = 12in = 0.3m
Exit diameter; d2 = 24 in = 0.6m
Volume flow rate of water; Q2 = 10 ft³/s = 0.28 m³/s
Initial pressure;p1 = 30 psi = 206843 pa
Thus,
initial Area;A1 = π•d1²/4 = π•0.3²/4 = 0.07 m²
Exit area;A2 = π•d2²/4 = π•0.6²/4 = 0.28m²
Now, we know that volume flow rate of water is given by; Q = A•V
Thus,
At exit, Q2 = A2•V2
So, 0.28 = 0.28•V2
So,V2 = 1 m/s
When flow is incompressible, we often say that ;
Initial mass flow rate = exit mass flow rate.
Thus,
ρ1 = ρ2 = 1000 kg/m³
Density of water is 1000 kg/m³
And A1•V1 = A2•V2
So, V1 = A2•V2/A1
So, V1 = 0.28 x 1/0.07
V1 = 4 m/s
So, from initial equation of y components;
-V1•ρ1•V1•A1 + V2•ρ2•V2•A2 = P1•A1 - P2•A2 - F_y
Where F_y is vertical force of enlargement pressure and P2 = 0
Thus, making F_y the subject;
F_y = P1•A1 + V1•ρ1•V1•A1 - V2•ρ2•V2•A2
Plugging in the relevant values to get;
F_y = (206843 x 0.07) + (1² x 1000 x 0.07) - (4² x 1000 x 0.28)
F_y = 151319.01N = 15.132 KN
Jasper and Gemma are going to play on a teeter totter. Gemma gets on first. When Jasper gets on, Gemma moves into the air, but she does not move to the top. Which statement could correctly explain the forces acting on the teeter totter? assume that Jasper and Gemma are the same distance from one another.
Answers
Answer:
A) the forces are balanced because Jasper weighs the same as Gemma
Explanation:
Answer:
A. The forces are balanced because Jasper weighs the same as Gemma.
Explanation:
Took the test
The arrival rate at a parking lot is 6 veh.min. Vehicles start arriving at 6:00PM and when the queue reaches 36 vehicles, service begins. If company policy is that total vehicle delay should be equal to 500 veh-min, what is the departure rate?
Answers
Answer:
Departure rate = 7.65 vehicle/min
Explanation:
See the attached file for the calculation.
A small vehicle is powered by a pulsejet. The available net thrust is 6000 N and the traveling speed is 200 km/hr. The gases leave the engine with an average velocity (Ve) of 360 m/s Assume pressure equilibrium exists at the outlet plane and the fuel to air ratio is 0.06.
a. Compute the mass flow rate required
b. Calculate the inlet area (assume To is 16 °C and Po is one atmosphere)
C. Calculate the thrust power
d. Calculate the propulsive efficiency
Answers
Answer:
a) The mass flow rate is 19.71 kg/s
b) The inlet area is 0.41 m²
c) The thrust power is 333.31 kW
d) The propulsive efficiency is 26.7%
Explanation:
Please look at the solution in the attached Word file.
Ethanol is produced in a one-liter batch fermenter by Saccharomyces cerevisiae (yeast). To begin the batch process, glucose and ammonia are added to the reactor, which has been inoculated by the yeast. The reaction produces glycerol and cell mass, in addition to ethanol, carbon dioxide, and water according to the (unbalanced) reaction below. Note that that the mass ratio of glycerol produced to glucose consumed is 0.2556. Also note that the mass ratio of H.O produced to NH, consumed is 1.058 Glucose + Ammonia → Glycerol + Ethanol + Yeast Cell Mass + Carbon Dioxide + Water a CH (8) + b NH(g)}p CH 0 (1) + (CHO) +ỊCH K04 Nụ (8) + $ 0 g) + t H (1) Balance the equation and fill out the table below. (1 point cach, 6 total) a- 1 b = 115 g of NH, are added to the reactor. At the end of the batch, 640 g of ethanol has been produced. How much glucose was added (assume complete conversion of the limiting reactant). mlar B 16 points) BONUS QUESTION USING CHAPTER 4 CONCEPTS: The standard heat of combustion (AHC) for the yeast is-22.1 kJ/mol. In order to maintain a constant temperature, how much heat must be added or removed from the reactor? Both the sign and magnitude of your answer will be graded J 3 points)
Answers
Answer:
Check the explanation
Explanation:
The process of Alcoholic fermentation involves the converting a single mole of glucose into two moles of carbon dioxide and two moles of ethanol, and in the process producing two moles of ATP. The total chemical formula for alcoholic fermentation is: C6H12O6 → 2 C2H5OH + 2 CO. Sucrose is a dimer of fructose and glucose molecules.
Kindly check the attached image below to see the full step by step explanation to the question above.
The ice on the rear window of an automobile is defrosted by attaching a thin, transparent, film type heating element to its inner surface. By electrically heating this element, a uniform heat flux may be established at the inner surface. The inside air temperature and convection heat transfer coefficient are T,i = 25°C and hi = 25 W/(m2 -K), while the outside air temperature is T,o = -10°C. For 4-mm thick window glass, determine (a) the electric power required per unit window area to maintain an inner surface temperature of 15°C and (b) the thermal conductivity of the windshield.
Answers
Answer:
A)Q = 1208.33 W/m²
B)K = 0.138 W/m.K
Explanation:
We are given;
inside air temperature;T_∞,i =25 °C = 25 + 273 = 298K
outside air temperature;T_∞,o = -10°C = - 10 + 273 = 263K
Inner surface temperature;T_s,i = 15 °C = 15 + 273 = 288K
Thickness, L = 4mm = 0.004m
convection heat transfer coefficient ; hi = 25 W/(m².K)
A) From an energy balance at the inner surface and the thermal circuit, the electric power required per unit window area is given as;
Q = [(T_s,i - T_∞,o)/((L/k) + (1/hi))] - [(T_∞,o - T_s,i)/(1/hi)]
Plugging in the relevant values with k for glass as 1.4 W/m.k, we have;
Q = [(288 - 263)/((0.004/1.4) + (1/25))] - [(263 - 288)/(1/25)]
Q = 583.33 + 625
Q = 1208.33 W/m²
B) The formula for thermal conductivity is;
K = (QL)/(AΔT)
Where;
K is the thermal conductivity in W/m.K
Q is the amount of heat transferred through the material
L is the distance between the two isothermal planes
A is the area of the surface in square meters
ΔT is the difference in temperature in Kelvin
ΔT = 298K - 263K = 35K
Now, since we have value of heat per unit area to be Q = 1208.33 W/m², let's rearrange the equation to reflect that; Thus ;
k = (Q/A) x (L/ΔT)
K = 1208.33 x (0.004/35)
K = 0.138 W/m.K
Consider airflow over a plate surface maintained at a temperature of 220°C. The temperature profile of the airflow is given as fluid ()()expsV TyTTTy The airflow at 1 atm has a free stream velocity and temperature of 0.08 m/s and 20°C, respectively. Determine the heat flux on the plate surface and the convection heat transfer coefficient of the airflow.
Answers
Consider airflow over a plate surface maintained at a temperature of 220°C. The temperature profile of the airflow is given as T(y) = T∞ − (T∞−Ts)exp((−V/α_fluid)y).
The airflow at 1 atm has a free stream velocity and temperature of 0.08 m/s and 20°C, respectively. Determine the heat flux on the plate surface and the convection heat transfer coefficient of the airflow
Answer:
A) heat flux on the plate is;q_o = 11737.34 W/m²
B) convection heat transfer coefficient of the airflow is;h = 58.67 W/m².k
Explanation:
The temperature profile of the airflow is given as;
T(y) = T∞ − (T∞−Ts)exp((−V/α_fluid)y)
Let's differentiate with respect to y;
dT/dy = [[(T∞−Ts)V]/α](e^(-vy/α)
Where;
T∞ = 20°C
Ts = 220°C
V = 0.08 m/s
α is thermal diffusivity of air and from the table i attached at a temperature of 220°C, by interpolation it has a value of;
α = 5.33 x 10^(-5) m²/s
Thus, at y =0;
dT/dy = [[(20 − 220)0.08]/(5.33 x 10^(-5))](e^(0))
dT/dy = -300187.62 °C/m
A) Now, heat flux at y = 0 would be given by;
q_o = -k(dT/dy)
Where k is thermal conductivity
from the table attached at 220°C and by interpolation, the thermal conductivity k = 0.0391 W/m.k
Thus,
q_o = -0.0391(-300187.62)
q_o = 11737.34 W/m²
B) the convection heat transfer coefficient of the airflow is gotten from;
q_o = h(Ts - T∞).
Where h is the convection heat transfer coefficient of the airflow
Thus making h the formula, we have;
h = q_o/(Ts - T∞)
h = 11737.34/(220 - 20)
h = 58.67 W/m².k
A plate of an alloy steel has a plane-strain fracture toughness of 50 MPa√m. If it is known that the largest surface crack is 0.5 mm long and that the value of Y is 1.1, which of the following can be said about this plate when a tensile stress of 1000 MPa is applied?
A. It is not possible to determine whether or not the plate will fracture.
B. The plate will definitely not fracture
C. The plate will definitely fracture.
Answers
Answer:
option B is correct. Fracture will definitely not occur
Explanation:
The formula for fracture toughness is given by;
K_ic = σY√πa
Where,
σ is the applied stress
Y is the dimensionless parameter
a is the crack length.
Let's make σ the subject
So,
σ = [K_ic/Y√πa]
Plugging in the relevant values;
σ = [50/(1.1√π*(0.5 x 10^(-3))]
σ = 1147 MPa
Thus, the material can withstand a stress of 1147 MPa
So, if tensile stress of 1000 MPa is applied, fracture will not occur because the material can withstand a higher stress of 1147 MPa before it fractures. So option B is correct.
Determine the angle φ at which the applied force P should act on the pipe so that the magnitude of P is as small as possible for pulling the pipe up the incline. What is the corresponding value of P? The pipe weighs W and the slope α is known. Express the answer in terms of the angle of static friction, θ = tan-1 μs.
Answers
Answer:
∅=Ф
P = W sin([tex]\alpha[/tex] + Ф)
Explanation:
First, we'll isolate and draw the free-body diagram of the pipe
Note that since the pipe is moving, the friction force is equal to the product of normal reaction force and the kinetic coefficient of friction
F = F_max = u_kN
Also note that the weight makes with the y-axis angle a because the x-axis makes the same angle with the horizontal
The expression for angle of friction is:
B = tan-1 (u_k)
From here we can express the coefficient of friction as:
u_k = tan(Ф)
Replace u_s by tan(Ф) in the expression for the friction force
F = N tan(Ф)
diagram is attached
By equating sum of forces in y-direction to zero, we can write the expression for the normal reaction force
ΣF_y = 0
N — W cos[tex]\alpha[/tex]- P sin Ф= 0
From here we can express N as:
N = W cos[tex]\alpha[/tex] -— P sin Ф
Replace N by the expression above in the expression for friction force F(written in step 1)
F = (W cos[tex]\alpha[/tex] — P sin Ф) tan( Ф) (1)
Now, we'll equate sum of forces in x-direction to zero
ΣF_x = 0
-F - W cos[tex]\alpha[/tex] + P sin Ф =0
Replace F by expression (1)
— (W cos[tex]\alpha[/tex] — P sin Ф) tan(Ф) — W sin[tex]\alpha[/tex]+pcosФ=0
-W cos [tex]\alpha[/tex] tan(Ф) + P sin Ф tan(Ф) — W sin[tex]\alpha[/tex] +pcosФ=0
P(sin Ф tan(Ф) + cosФ) — W(cos [tex]\alpha[/tex] tan(Ф) + sin [tex]\alpha[/tex])
From here we can express the force P needed to pull the pipe as:
P = W(cos[tex]\alpha[/tex] tan(Ф) + sin[tex]\alpha[/tex])/sinФ*tansФ+cosФ (2)
All we have to do now is to simplify the expression (2). We'll start by sin replacing tan(Ф) with sinФ/cosФ
P = W(cos *sinФ/cosФ + sin)/sinФ*sinФ/cosФ+cosФ *cosФ/cosФ
We can multiply the right side of equation by cosФ/cosФ
P = W(cos[tex]\alpha[/tex] *sinФ + sin[tex]\alpha[/tex]cosФ)/sin∅*sinФ+cos∅cosФ *cosФ/cosФ
Finally, we'll replace (cos[tex]\alpha[/tex] *sinФ + sin[tex]\alpha[/tex]cosФ) by sin([tex]\alpha[/tex] + Ф) and (sin∅ sinФ + cos∅ cos Ф) by cos( ∅— Ф)
P wsin([tex]\alpha[/tex] + Ф) /cos(∅ — Ф) (3)
Since the first derivative of the function is actually tangens of the angle which tangent makes with the x-axis, we'll find it by equating the first derivative by zero(this means that the tangent of the function is horizontal, i.e. that the function is at its maximum or minimum)
Note that the variable in the expression (3) is 0, since both B and a are known
dP/d∅ =d/d∅ [sin(Ф+)/cos(∅-Ф) ]
Note that sin(Ф+[tex]\alpha[/tex]) is constant since both Ф and a are known
dP/d∅ = sin(Ф+[tex]\alpha[/tex]) d/dФ [1/cos(∅-Ф) ]
Next, we'll apply the reciprocal rule
= -dP/d∅[cos(∅-Ф)]/cos^2(∅-Ф)*sin(Ф+[tex]\alpha[/tex])
Next, we'll apply the differentiation rule
=(-sin(∅-Ф))*d/d∅[∅-Ф]*sin(Ф+[tex]\alpha[/tex])/cos^2(∅-Ф)
=(d/d∅[∅]+d/d∅[-∅])*sin(Ф+[tex]\alpha[/tex])sin(∅-Ф)/cos^2(∅-Ф)
dP/d∅ =sin(Ф+[tex]\alpha[/tex])*sin(∅-Ф)/cos^2(∅-Ф) (4)
Next step will be to equate the expression (4) to zero, to determine the value of # when the function is minimum
sin(Ф+[tex]\alpha[/tex])*sin(∅-Ф)/cos^2(∅-Ф) =0
Note that sin(Ф+[tex]\alpha[/tex]) is constant, so in order for the equation above to be correct, sin(∅-Ф) needs to be equal to zero
sin(∅-Ф) = 0
Since sin 0° = sin 180° = 0, two possible solutions for ∅ are:
∅-Ф=0 Ф=∅
or
∅-Ф = 180° ∅ = 180° + Ф
Since the function for P is only good over the range 0 < ∅ < 90°, since when > 90° the friction force will change its direction, we can conclude that the minimum force P is required to move the pipe at angle:
∅=Ф
Finally, replace # by 8 in expression (3) to determine the minimum force P required to move the pipe
P = W sin([tex]\alpha[/tex] + Ф ) / cos ∅ — ∅)
P = W sin([tex]\alpha[/tex] + Ф)
(Using Python)Part 2aNumerology is the "study of the purported mystical or special relationship between a number and observed or perceived events." It has been used throughout human history as a way to attach meaning to a name, object or event using mathematics. It is considered a "pseudoscience" by modern scientists since it has no basis in observable phenomena. With that said, it makes a great programming challenge so we're going to go with it! :)What you want to do for this project is to ask the user to type in their name. Next, you will need to use a technique called "theosophical reduction" to convert their name into a number. With this technique we assign each letter of the alphabet its own number. For example, the letter "a" is equal to the number 1. "b" = 2, "c" = 3, "z" = 26, etc. You should ignore non-alphabetic characters (i.e. numbers, spaces and special characters)Once you've gotten all of the letters converted into numbers you can add them up into one single number. This is the "numerology number" for the name that the user entered.So for the name "craig" the numerology number would be:c = 3r = 18a = 1i = 9g = 73 + 18 + 1 + 9 + 7 = 38Here's are a few sample runnings of this program:Name: craigYour 'cleaned up' name is: craigReduction: 38Name: craig kappYour 'cleaned up' name is: craigkappReduction: 82Name: rumple stil skinYour 'cleaned up' name is: rumplestilskinReduction: 198Name: !rumple!stil!skinYour 'cleaned up' name is: rumplestilskinReduction: 198Name: pikachu!pikapika!Your 'cleaned up' name is: pikachupikapikaReduction: 143Name: PIKACHUpikapikaYour 'cleaned up' name is: pikachupikapikaReduction: 143Some hints:Convert the user's name to all uppercase or all lowercase before you do anything elseRemove any spaces, numbers or special characters from the name to ensure that you are only working with the letters A-ZThe ord() function may be userful to convert each character into an ASCII index
Answers
Answer:
See explaination for python programming code
Explanation:
Python programming code below
import re
s = "abc" # enter string here
#s = "hello world! HELLOW INDIA how are you? 01234"
# Short version
print filter(lambda c: c.isalpha(), s)
# Faster version for long ASCII strings:
id_tab = "".join(map(chr, xrange(256)))
tostrip = "".join(c for c in id_tab if c.isalpha())
print s.translate(id_tab, tostrip)
# Using regular expressions
s1 = re.sub("[^A-Za-z]", "", s)
s2 = s1.lower()
print s2
import string
values = dict()
for index, letter in enumerate(string.ascii_lowercase):
values[letter] = index + 1
sum = 0
for ch2 in s2:
for ch1 in values:
if(ch2 == ch1):
sum = sum + values[ch1]
print sum
Design a Mealy machine for a 20 cent candy dispensing machine which accepts nickel (n) , dime (d) and quarter(q) . It gives candy as well change in the form of nickels only. To help you, here are the some of the elements of the machine: States: 0, 5, 10 and 15 represent the amount of money already inserted in the machine. n, d and q representing coins inserted in the machine Output: c0 (candy and no change), c1 (one nickel as change), c2(two nickels as change ), c3 (three nickels as change), and c4 (four nickels as change)
Answers
Find the answer in the attachment
A minor road intersects a major 4-lane divided road with a design speed of 55mph and a median width of 8 feet. The intersection is controlled with a stop sign on the minor road. If the design vehicle is a passenger car, determine the minimum sight distance required on the major road that will allow a stopped vehicle on the minor road to safely turn left if the approach grade on the minor road is 3%.
Answers
Answer:
stopping sight diatnce is =158 meters
Explanation:
The Design Speed =55 MPH(Miles per Hour)
1 miles per hour =0.447 meter pe second
then 55MPH=55*0.447=24.58 meter per second
Consider recation time =2.5 second
Consider Co efficinet friction is 0.35
As per the Stopping sight distance based on the Breaking distance+ Lag distance
SSD=Vt+(V^2/(2gf))
SSD=24.58+(24.58^2/(2*9.81*0.35))
The total stopping sight distance is =150 meters
if we consider the Approaching garde on the minor road is 3%
SSD=Vt+(V^2/(2g(f-n/100))
SSD=24.58+(24.58^2/(2*9.81*(0.35-3/100))
then stopping sight diatnce is =158 meters
See attachment for workings
Neglecting the presence of friction, air drag, and other inefficiencies, how much gasoline is consumed when a 1300 kg automobile accelerates from rest to 80 km/h. Assume the density and enthalpy of gasoline are 680 kg/m3 and 45 MJ/kg respectively. Express your answer in the units of mL. Show all work and use SI units for full credit. Box your final answer(s)
Answers
Answer:
Explanation:
Given that, .
Mass of car is
M = 1300kg
Velocity of car
V = 80km/h = 80 × 1000/3600
V = 22.22m/s
Calculate the kinetic energy of the vehicle as follows:
K.E = ½ MV²
K.E = ½ × 1300 × 22.22²
K.E = 320,987.65 J
Given that,
Enthalpy is 45MJ / kg
h = 45MJ / kg
Then, enthalpy is given as.
Enthalpy = Energy / mass
h = E / m
45 × 10^6 = 320,987.65 / m
m = 320,987.65 / 45 × 10^6
m = 7.133 × 10^-3 kg
m = 7.133 mg
Also, given that, density is 680kg/m³
Density is given as
Density = mass / Volume
ρ = m / v
Then, v = m / ρ
v = 7.133 × 10^-3 / 680
v = 1.049 × 10^-5 m³
We know that
1mL = 10^-6 m³
Therefore,
v = 1.049 × 10^-5 m³ × 1mL / 10^-6m³
v = 10.49 mL
You are provided the following information about a municipal wastewater treatment plant. This plant uses the traditional activated-sludge process.
Assume the microorganisms are 55 percent efficient at converting food to biomass, the organisms have a first-order death rate constant of 0.05/day, and the microbes reach half of their maximum growth rate when the BOD5 concentration is 10 mg/L. There are 150,000 people in the community (their wastewater production is 225 L/day-capita, 0.1 kg BOD5/capita-day). The effluent standard is BOD5 = 20 mg/L and TSS = 20 mg/L.
Suspended solids were measured as 4,300 mg/L in a wastewater sample obtained from the biological reactor, 15,000 mg/L in the secondary sludge, 200 mg/L in the plant influent, and 100 mg/L in the primary clarifier effluent. SRT is equal to 4 days.
(a) What is the design volume of the aeration basin (m3)?
(b) What is the plant
Answers
Answer:
Explanation:
Attached is the solution
The air velocity in the duct of a heating system is to be measured by a Pitot-static probe inserted into the duct parallel to the flow. The differential height between the water columns connected to the two outlets of the probe is 0.126 m.Take the density of water to be 1000 kg/m3. The gas constant of air is R = 0.287 kPa-m3/kg-K.The air temperature and pressure in the duct are 352 K and 98 kPa, respectively.
Answers
Answer:
Flow velocity
50.48m/s
Pressure change at probe tip
1236.06Pa
Explanation:
Question is incomplete
The air velocity in the duct of a heating system is to be measured by a Pitot-static probe inserted into the duct parallel to the flow. If the differential height between the water columns connected to the two outlets of the probe is 0.126m, determine (a) the flow velocity and (b) the pressure rise at the tip of the probe. The air temperature and pressure in the duct are 352k and 98 kPa, respectively
solution
In this question, we are asked to calculate the flow velocity and the pressure rise at the tip of probe
please check attachment for complete solution and step by step explanation