Solution :
For R-134a, we are given :
[tex]$T_i = 25^\circ C$[/tex]
[tex]$P_i=750 \ kPa$[/tex]
[tex]$P_e=165 \ kPa$[/tex]
Now we have one inlet and one exit flow, no work and no heat transfer. The energy equation is :
[tex]$h_e+\frac{1}{2}.v_e^2= h_i+\frac{1}{2}.v_i^2 $[/tex]
We also know that the gas is throttled and there is no change in the kinetic energy.
So, [tex]$v_e=v_i$[/tex]
Now from the energy equation above, we can see that the inlet and the exit enthalpies are also the same. Therefore,
[tex]$h_i=h_e$[/tex]
From the saturated R-134a table, corresponding to [tex]P_e = 165 \ kPa[/tex], we can find the exit saturation temperature.
[tex]$T_e=-15^\circ C$[/tex]
From the saturated R-134a table, corresponding to [tex]P_e = 165 \ kPa[/tex], we can find the specific enthalpies :
[tex]$h_f = 180.19 \ kJ/kg$[/tex]
[tex]$h_{fg} = 209 \ kJ/kg$[/tex]
Calculating the exit flow quality factor,
[tex]$x_e=\frac{h_e-h_f}{h_{fg}}$[/tex]
[tex]$=\frac{234.59-180.19}{209}$[/tex]
= 0.26
From the saturated R-134a table, corresponding to [tex]P_e = 165 \ kPa[/tex], we can find the specific volumes :
[tex]$v_f = 0.00746 \ m^3/kg$[/tex]
[tex]$v_{fg} = 0.11932 \ m^3/kg$[/tex]
Calculating the exit specific volume :
[tex]$v_e=v_f+x_e(v_{fg})$[/tex]
= 0.000746 + 0.26 (0.11932)
= 0.0318 [tex]m^3/kg[/tex]
The mass flow is equal to :
[tex]$\dot{m} = A_i . \frac{v}{v_i}$[/tex]
[tex]$=A_e . \frac{v}{v_e}$[/tex]
So, [tex]$\frac{A_e}{A_i}=\frac{v_e}{v_i}$[/tex]
Therefore, the ratio of the exit pipe and the inlet pipe diameter is equal to
[tex]$\frac{D_e}{D_i}=\sqrt{\frac{A_e}{A_i}}$[/tex]
[tex]$\frac{D_e}{D_i}=\sqrt{\frac{v_e}{v_i}}$[/tex]
[tex]$\frac{D_e}{D_i}=\sqrt{\frac{0.0318}{0.000829}}$[/tex]
[tex]$\frac{D_e}{D_i}=6.19$[/tex]
Please label the following statements as either True (T) or False (F).
(a) The true stress is higher than the engineering stress for a sample under tension.
(b) Creep test is carried out with a dynamic stress under elevated temperature.
Answer:
a. True
b. False
Explanation:
a. Since true stress, σ' = σ(1 + ε) where σ = engineering stress and ε = engineering strain.
Also under tension ε > 0, so, (1 + ε) > 1
Since (1 + ε) = σ'/σ > 1, ⇒ σ' > σ
So, the true stress is greater than the engineering stress.
So, the statement is true
b. Creep is a time-dependent deformation under certain applied load.
Creep occurs at high temperatures under different types of stress.
But, Creep test is carried out at constant high temperature and constant stress.
This statement is false.
list 3 appliances each of the following
soil
waste
Answer:
soil>>Slop sink
>Urinal
>water closet
Here are the city gas mileages for 13 different midsized cars in 2008. 16, 15, 22, 21, 24, 19, 20, 20, 21, 27 , 18 , 21 , 48 What is the minimum ?
Answer:
Minimum city gas mileage is 15
Explanation:
Minimum city gas mileage among 13 different car sizes in 2008 is 15.
khái niệm về môi trường nhiệt nóng và môi trường nhiện lạnh ?
ảnh hưởng của môi trường và môi trường nhiệt lạnh đến con người như thế nào ?
Theo em môi trường nào gây nguy hiểm hơn đối với con người ? Vì sao ?
Explanation:
उह्ह्नमजज्ल्ह्ह्बनुतनकुहक्जो
A copper block receives heat from two different sources: 5 kW from a source at 1500 K and 3 kW from a source at 1000 K. It loses heat to atmosphere at 300 K. Assuming the block to be at steady state, determine (a) the net rate of heat transfer in kW; (b) the rate of entropy generation in the system's universe
Answer:
a) Zero
b) the rate of entropy generation in the system's universe = ds/dt = 0.2603 KW/K
Explanation:
a) In steady state
Net rate of Heat transfer = net rate of heat gain - net rate of heat lost
Hence, the rate of heat transfer = 0
b) In steady state, entropy generated
ds/dt = - [ Qgain/Th1 + Qgain/Th2 - Qlost/300 K]
Substituting the given values, we get –
ds/dt = -[5/1500 + 3/1000 – (5+3)/300]
ds/dt = - [0.0033 + 0.003 -0.2666]
ds/dt = 0.2603 KW/K
16) Find the output of the following flowchart
Address
100
101
102
103
104
105
Value
1
2.
3
8
15
16
hi
Answer:80
Answer:
364 566 inches of class-6th from a
Một máy nghiền bi thùng ngắn đường kính D = 1.6m, dài L = 2m dùng để nghiền VL. Kích thước đầu vào D1 = 20mm, sản phẩm sau nghiền có kết quả phân tích rây sau:
Số mesh
60/80
80/100
100/150
150/200
Khối lượng VL trên rây
0.1
0.3
2.5
0.1
Hỏi
1. Tính kích thước bi nghiền bi.
2. Tính số vòng quay tối ưu.
3. Tính năng suất (biết K1 = 1.01).
4. Tính số lượng bi cần nạp vào thùng. Biết hệ số chứa đầy φ = 0.25, hệ số rỗng = 0.65, ⍴bi = 8000 kg/m3
Answer:
bood ekogcd gcaerh is an American fbnuxc
If the two 304-stainless-steel carriage bolts of the clamp each have a diameter of 10 mmmm, and they hold the cylinder snug with negligible force against the rigid jaws, determine the temperature at which the average normal stress in either the magnesium or the steel first becomes 12.0 MPaMPa .
Answer: hello some data related to your question is missing attached below is the missing data
answer:
T2 = 265°C
Explanation:
First step : calculate sum of vertical forces
∑ y = 0
Fmg - 2(0.5 Fst ) = 0
∴Fmg = ( 12 * 10^6 ) ( 2 * π/4 (0.01)^2 )
= 1884.96 N
Also determine the Compatibility equation in order to determine the change in Temperature
ΔT = 250°C
therefore Temperature at which average normal stress becomes 12.0 MPa
ΔT = T2 - T1
250°C = T2 - 15°C
T2 = 250 + 15 = 265°C
attached below is the detailed solution
Nguyên lý hoạt động của cảm biến áp điện là gì?
Answer:
Nguyên lý hoạt động của cảm biến từ
Cảm biến từ có nguyên lý hoạt động khá đơn giản. Theo đó, một cuộn cảm sẽ phát triển một từ trường khi có dòng điện chạy qua nó; hay nói cách khác một dòng điện sẽ chạy qua một mạch chứa cuộn cảm khi từ trường xuyên qua nó thay đổi.
Ngoài ra, hiệu ứng này còn có thể được sử dụng để phát hiện các vật kim loại có tương tác với từ trường. Các chất phi kim loại như chất lỏng hay một số loại bụi bẩn không tương tác với từ trường. Do đó, cảm biến từ hoàn toàn có thể hoạt động được trong điều kiện ẩm ướt hoặc bụi bẩn.
Explanation:
Ideally speaking, bonds tend to form between two particles such that they are separated by a distance where force is exerted on them, and their overall energy is:________
a. a negative, minimized
b. a positive, minimized
c. zero, minimized
d. zero, maximized
e. a positive, maximized
f. a negative, maximized
Answer:
a g i
Explanation:
nnj
Just because I seen someone else ask but they didn't have enough information.
If a filesystem has a block size of 4096 bytes, this means that a file comprised of only one byte will still use 4096 bytes of storage. A file made up of 4097 bytes will use 4096*2=8192 bytes of storage. Knowing this, can you fill in the gaps in the calculate_storage function below, which calculates the total number of bytes needed to store a file of a given size?
Answer:
Following are the program to the given question:
def calculate_storage(filesize):#definging a method calculate_storage that takes filesize as a parameter
block_size = 4096#definging block_size that holds value
full_blocks = filesize//block_size#definging full_blocks that divides the value and hold integer part
partial_block_remainder = filesize%block_size#definging partial_block_remainder that holds remainder value
if partial_block_remainder > 0:#definging if that compare the value
return block_size*full_blocks+block_size#return value
return block_size*full_blocks#return value
print(calculate_storage(1)) # calling method by passing value
print(calculate_storage(4096)) # calling method by passing value
print(calculate_storage(4097)) # calling method by passing value
Output:
4096
4096
8192
Explanation:
In this code, a method "calculate_storage" is declared that holds a value "filesize" in its parameters, inside the method "block_size" is declared that holds an integer value, and defines "full_blocks and partial_block_remainder" variable that holds the quotient and remainder value and use it to check its value and return its calculated value. Outside the method, three print method is declared that calls the method and prints its return value.
1. What is the maximum value of the linear density in a crystalline solid (linear density defined as the fraction of the line length occupied by atoms, assumed as spheres and only counted it their center is on the line)?
2. What family of directions has the highest linear density in the FCC system?
3. What family of directions has the highest linear density in the BCC system?
4. What family of planes has the highest planar density in the FCC system?
5. What family of planes has the highest planar density in the BCC system?
6. What family of planes has the highest planar density in the HCP sytem?
Request for proposal (RFP) is a type of document that contains the information and proposals mostly through the bidding process. This document is regarding the valuable assets, services, entity, commodity, etc.
Answer:
Answer to the following is as follows;
Explanation:
A request for proposal is a documentation that invites prospective contractors to submit business opportunities to an agency or corporation interested in procuring a commodities, product, or valuable resource through a bid procedure.
A request for proposal (RFP) is a commercial document that introduces a project, defines it, and invites eligible contractors to compete on its completion.
