Answer:
q' = 5826 W/m
Explanation:
Given:-
- The length of the rectangular fin, L = 0.15 m
- The surface temperature of fin, Ts = 250°C
- The free stream velocity of air, U = 80 km/h
- The temperature of air, Ta = 27°C
- Parallel flow over both surface of the fin, assuming turbulent conditions through out.
Find:-
What is the rate of heat removal per unit width of the fin?
Solution:-
- Assume steady state conditions, Negligible radiation and flow conditions to be turbulent.
- From Table A-4, evaluate air properties (T = 412 K, P = 1 atm ):
Dynamic viscosity , v = 27.85 * 10^-6 m^2/s
Thermal conductivity, k = 0.0346 W / m.K
Prandlt number Pr = 0.69
- Compute the Nusselt Number (Nu) for the - turbulent conditions - the appropriate relation is as follows:
[tex]Nu = 0.037*Re_L^\frac{4}{5} * Pr^\frac{1}{3}[/tex]
Where, Re_L: The average Reynolds number for the entire length of fin:
[tex]Re_L = \frac{U*L}{v} \\\\Re_L = \frac{80*\frac{1000}{3600} * 0.15}{27.85*10^-^6} \\\\Re_L = 119688.80909[/tex]
Therefore,
[tex]Nu = 0.037*(119688.80909)^\frac{4}{5} * 0.69^\frac{1}{3}\\\\Nu = 378[/tex]
- The convection coefficient (h) can now be determined from:
[tex]h = \frac{k*Nu}{L} \\\\h = \frac{0.0346*378}{0.15} \\\\h = 87 \frac{W}{m^2K}[/tex]
- The rate of heat loss q' per unit width can be determined from convection heat transfer relation, Remember to multiply by (x2) because the flow of air persists on both side of the fin:
[tex]q' = 2*[h*L*(T_s - T_a)]\\\\q' = 2*[87*0.15*(250 - 27)]\\\\q' = 5826\frac{W}{m}[/tex]
- The rate of heat loss per unit width from the rectangular fin is q' = 5826 W/m
- The heat loss per unit width (q') due to radiation:
[tex]q' = 2*a*T_s^4*L[/tex]
Where, a: Stefan boltzman constant = 5.67*10^-8
[tex]q' = 2*5.67*10^-^8*(523)^4*0.15\\\\q' = 1273 \frac{W}{m}[/tex]
- We see that radiation loss is not negligible, it account for 20% of the heat loss due to convection. Since the emissivity (e) of the fin has not been given. So, in the context of the given data this value is omitted from calculations.
An offset h must be introduced into a metal tube of 0.75-in. outer diameter and 0.08-in. wall thickness. Knowing that the maximum stress after the offset is introduced must not exceed 4 times the stress in the tube when it is straight, determine the largest offset that can be used
Complete Question
The diagram for this question is shown on the first uploaded image
Answer:
The largest offset that can be used is [tex]h = 0.455 \ in[/tex]
Explanation:
From the question we are told that
The diameter of the metal tube is [tex]d_m = 0.75 \ in[/tex]
The thickness of the wall is [tex]D = 0.08 \ in[/tex]
Generally the inner diameter is mathematically evaluated as
[tex]d_i = d_m -2D[/tex]
[tex]= 0.75 - 2(0.08)[/tex]
[tex]= 0.59 \ in[/tex]
Generally the tube's cross-sectional area can be evaluated as
[tex]a = \frac{\pi}{4} (d_m^2 - d_i^2)[/tex]
[tex]= \frac{\pi}{4} (0.75^2 - 0.59^2)[/tex]
[tex]= 0.1684 \ in^2[/tex]
Generally the maximum stress of the metal is mathematically evaluated as
[tex]\sigma = \frac{P}{A}[/tex]
[tex]\sigma = \frac{P}{ 0.1684}[/tex]
The diagram showing when the stress is been applied is shown on the second uploaded image
Since the internal forces in the cross section are the same with the force P and the bending couple M then
[tex]M = P * h[/tex]
Where h is the offset
The maximum stress becomes
[tex]\sigma_n = \frac{P}{A} + \frac{M r_m }{I}[/tex]
Where [tex]r_m[/tex] is the radius of the outer diameter which is evaluated as
[tex]r_m = \frac{0.75}{2}[/tex]
[tex]r_m = 0.375 \ in[/tex]
and I is the moment of inertia which is evaluated as
[tex]I = \frac{\pi}{64} (d_m^4 - d_i^4 )[/tex]
[tex]= \frac{\pi}{64}(0.75^4 - 0.59^4)[/tex]
[tex]= 0.009583 \ in^4[/tex]
So the maximum stress becomes
[tex]\sigma' = \frac{P}{0.1684} + \frac{Phr}{0.009583}[/tex]
Now the question made us to understand that the maximum stress when the offset was introduced must not exceed the 4 times the original stress
So
[tex]\sigma ' = 4 \sigma[/tex]
=> [tex]\frac{P}{0.1684} + \frac{Phr_m }{0.009583} = 4 [\frac{P}{0.1684} ][/tex]
The P would cancel out
[tex]\frac{1}{0.1684} + \frac{h(0.375)}{0.009583} = \frac{4}{0.1684}[/tex]
[tex]5.94 + 39.13h = 23.753[/tex]
[tex]39.13h = 17. 813[/tex]
[tex]h = 0.455 \ in[/tex]
6msection of 150lossless line is driven by a source with vg(t) = 5 cos(8π × 107t − 30◦ ) (V) and Zg = 150 . If the line, which has a relative permittivity r = 2.25, is terminated in a load ZL = (150 − j50) , determine: (a) λ on the line. ∗ (b) The reflection coefficient at the load. (c) The input impedance. (d) The input voltage Vi. (e) The time-domain input voltage vi(t).
Answer:
a. 5m
b. r = 0.16 e^-80.5◦
c. Zpn = (115.7 + j27.4) ohms
d. Vi = 2.2e^-j22.56◦ volts
e. Vi(t) = 2.2 cos (8π × 107t − 22.56◦ ) Volts
Explanation:
In this question, we are tasked with calculating a series of terms.
Please check attachment for complete solution and step by step explanation
The piping system that connects one reservoir to a second reservoir consists of 150-ft of 3-in. cast iron pipe that has four flanged elbows, a well-rounded entrance, and sharp-edged exit, and a fully open gate valve. For 75 gal/min of water at 50 °F, determine the elevation difference between the two reservoirs (in ft).
The elevation difference between the two reservoirs is 10.28 ft
Given information:
- Length of the 3-in. cast iron pipe = 150 ft
- Number of flanged elbows = 4
- Entrance condition: well-rounded
- Exit condition: sharp-edged
- Fully open gate valve
- Flow rate = 75 gal/min
- Water temperature = 50 °F
Step 1: Convert the flow rate from gal/min to ft³/s.
Flow rate in ft³/s = (75 gal/min) × (1 ft³/7.48 gal) × (1 min/60 s) = 0.167 ft³/s
Step 2: Calculate the velocity of flow.
Velocity of flow, V = Flow rate / Cross-sectional area of the pipe
Cross-sectional area of the 3-in. cast iron pipe = (π/4) × (3/12)² ft² = 0.0491 ft²
Velocity of flow, V = 0.167 ft³/s / 0.0491 ft² = 3.4 ft/s
Step 3: Calculate the Reynolds number to determine the flow regime.
Reynolds number, Re = (ρVD) / μ
Where,
ρ = density of water at 50 °F = 1.94 slugs/ft³ (from tables)
V = velocity of flow = 3.4 ft/s
D = diameter of the pipe = 3/12 ft
μ = dynamic viscosity of water at 50 °F = 2.73 × 10⁻⁵ lb.s/ft² (from tables)
Re = (1.94 slugs/ft³) × (3.4 ft/s) × (3/12 ft) / (2.73 × 10⁻⁵ lb.s/ft²) = 1.9 × 10⁵
Since Re > 4000, the flow is turbulent.
Step 4: Calculate the head loss due to friction in the straight pipe.
Head loss due to friction, hf = f × (L/D) × (V²/2g)
Where,
f = friction factor (depends on Reynolds number and pipe roughness)
L = length of the pipe = 150 ft
D = diameter of the pipe = 3/12 ft
V = velocity of flow = 3.4 ft/s
g = acceleration due to gravity = 32.2 ft/s²
From the Moody diagram or friction factor tables for cast iron pipe, assuming a relative roughness of 0.00085, and Re = 1.9 × 10⁵, the friction factor, f = 0.021.
Substituting the values, hf = 0.021 × (150 × 12/3) × [(3.4)²/(2 × 32.2)] = 8.4 ft
Step 5: Calculate the head loss due to fittings (elbows, entrance, exit, and valve).
Head loss due to fittings, hf_fittings = Σ(K × V²/2g)
Where K is the loss coefficient for each fitting.
For 4 flanged elbows, K = 0.3 (for each elbow)
For a well-rounded entrance, K = 0.03
For sharp-edged exit, K = 1.0
For a fully open gate valve, K = 0.2
Substituting the values, hf_fittings = [4 × 0.3 + 0.03 + 1.0 + 0.2] × [(3.4)²/(2 × 32.2)] = 1.7 ft
Step 6: Calculate the velocity head.
Velocity head, hv = V²/2g = (3.4)²/(2 × 32.2) = 0.18 ft
Step 7: Calculate the total head loss.
Total head loss, H = hf + hf_fittings + hv
H = 8.4 ft + 1.7 ft + 0.18 ft = 10.28 ft
Therefore, the elevation difference between the two reservoirs is 10.28 ft for the given piping system and a flow rate of 75 gal/min of water at 50 °F.
List the RTL (Register Transfer Language) sequence of micro-operations needed to execute the instruction
STORE X
from the MARIE instruction set architecture. Then write the corresponding signal sequence to perform these micro-operations and to reset the clock cycle counter.
You may refer to the provided "MARIE Architecture and Instruction Set" file in the Front Matter folder.
Answer:
So these are the RTL representation:
MAR<----X
MBR<-----AC
M[MAR]<------MBR
Control signal sequence are:
P3T0:MAR<----X
P2P3 P4T1:MBR<-----AC
P0P1 P3T2:M[MAR]<------MBR
Explanation:
STORE X instruction is used for storing the value of AC to the memory address pointed by X. This operation can be done by using the Register Transfers at System Level and this can be represented by using a notation called Register Transfer Language RTL. Let us see what are the register transfer operations happening at the system level.
1. First of all the address X has to be tranfered on to the Memory Address Register MAR.
MAR<----X
2. Next we have to tranfer the contents of AC into the Memory Buffer Register MBR
MBR<-----AC
3. Store the MBR into memory where MAR points to.
M[MAR]<------MBR
So these are the RTL representation:
MAR<----X
MBR<-----AC
M[MAR]<------MBR
Control signal sequence are:
P3T0:MAR<----X
P2P3 P4T1:MBR<-----AC
P0P1 P3T2:M[MAR]<------MBR
A pendulum is made of two rods that are firmly welded together to make a cross. The rod AB is 2 m long with a mass of 20 kg. The rod CD is 1 m long with a mass of 10 kg. Recall that for a rod the moment of inertia about its center of mass is given by IG = 1/12 m L2 cross2 What is the moment of inertia about A for member AB?
Answer:
IA = 80/3 kgm^2
Explanation:
Given:-
- The mass of rod AB, m1 = 20 kg
- The length of rod AB, L1 = 2m
- The mass of rod CD, m2 = 10 kg
- The length of rod CD, L2 = 1m
Find:-
What is the moment of inertia about A for member AB?
Solution:-
- The moment of inertia About point "O" the center of rod AB is given as:
IG = 1/12*m1*L^2
- To shift the axis of moment of inertia for any object at a distance "d" from the center of mass of that particular object we apply the parallel axis theorem. The new moment of inertia about any arbitrary point, which in our case A end of rod AB is:
IA = IG + m1*d^2
- Where the distance "d" from center of rod AB to its ends is 1/2*L1 = 1 m.
So the moment of inertia for rod AB at point A would be:
IA = 1/12*m1*L^2 + m1*0.5*L1^2
IA = 1/3 * m1*L1^2
IA = 1/3*20*2^2
IA = 80/3 kgm^2
A square hole is to be cut using ECM through a plate of low alloy steel that is 12 mm thick. The hole is 35 mm on each side, but the electrode used to cut the hole is slightly less than 35 mm on its sides to allow for overcut, and its shape includes a hole in its center to permit the flow of electrolyte and to reduce the area of the cut. This will produce a center core that can be removed after the tool breaks through. This tool design results in a frontal area of 245 mm2 . The applied current = 1200 amps.
Using an efficiency of 95%, how long will it take to cut the hole?
It will take approximately 0.0238 s to cut the hole.
To calculate the time required to cut the hole using Electrochemical Machining (ECM), we can use the following formula:
[tex]\text { Time }=\frac{\text { Volume of Material to be Removed }}{\text { Material Removal Rate (MRR) }}[/tex]
First, let's calculate the volume of material to be removed:
Volume of Material=Frontal Area × Thickness of Plate
Given:
[tex]Frontal Area =245 \mathrm{~mm}^2\\Thickness of Plate $=12 \mathrm{~mm}$[/tex]
Volume of Material = [tex]245 \mathrm{~mm}^2 \times 12 \mathrm{~mm}=2940 \mathrm{~mm}^3[/tex]
Next, we need to calculate the Material Removal Rate (MRR). MRR is usually given in units of volume removed per unit time per unit current density. Let's assume it is given as [tex]X \mathrm{~mm}^3 / \mathrm{min} / \mathrm{A} / \mathrm{mm}^2 .[/tex] Given the current density [tex]\text { Current Density }=\frac{\text { Applied Current }}{\text { Frontal Area }}[/tex], we can calculate the MRR as:
MRR=X×Current Density
Given:
Applied Current = 1200 A
Efficiency = 95%
Frontal Area = 245 [tex]mm^2[/tex]
[tex]\begin{aligned}& \text { Current Density }=\frac{\text { Applied Current }}{\text { Frontal Area }}=\frac{1200 \mathrm{~A}}{245 \mathrm{~mm}^2} \\& \text { Current Density } \approx 4.897 \mathrm{~A} / \mathrm{mm}^2\end{aligned}[/tex]
Let's assume X=0.2[tex]mm^3[/tex] /s/A/[tex]mm^2[/tex](hypothetical value).
[tex]\mathrm{MRR}=0.2 \times 4.897 \approx 0.979 \mathrm{~mm}^3 / \mathrm{s}[/tex]
To convert mm³/s to g/s, we need to know the density of the material. Let's assume the density of low alloy steel is approximately [tex]7.85 \mathrm{~g} / \mathrm{cm}^3[/tex], which is [tex]7.85 \times 10^{-6} \mathrm{~g} / \mathrm{mm}^3 .[/tex]
Now, we can calculate the MRR in grams per second:
[tex]MRR in $\mathrm{g} / \mathrm{s}=\mathrm{MRR} \times$ Density of material\\MRR in $\mathrm{g} / \mathrm{s}=0.979 \mathrm{~mm}^3 / \mathrm{s} \times 7.85 \times 10^{-6} \mathrm{~g} / \mathrm{mm}^3$\\MRR in $\mathrm{g} / \mathrm{s} \approx 0.00000768515 \mathrm{~g} / \mathrm{s}$[/tex]
Now, we can use these values to calculate the time required:
[tex]\text { Time }=\frac{2940 }{0.00000768515} \\& \text { Time } \approx 0.022594341[/tex]
However, we need to consider the efficiency. Since the efficiency is 95%, the actual time required will be:
[tex]\begin{aligned}& \text { Actual Time }=\frac{\text { Time }}{\text { Efficiency }} \\& \text { Actual Time }=\frac{0.022594341}{0.95}\end{aligned}[/tex]
≈ 0.0238 s
The fins are 90% efficient. Determine the minimum free-stream velocity the fan needs to supply to avoid overheating. Assume the flow is laminar over the entire finned surface of the transformer and check your assumption at the end. Assume the same convection heat transfer coefficient for the finned and unfinned area. Use 40 [C] for the film temperature.
Answer:
The minimum required free stream velocity required to dissipate 12W via fins is V∞ = 0.0020378 m/s = 2.0378 mm/s.
Explanation:
Given:-
- The dimension of transformer surface ( L , w , H ) = ( 10 cm long , 6.2 cm wide, 5 cm high )
- The dimensions of the fin : ( l , h , t ) = (10 cm long , 5 mm high, 2 mm thick )
- The total number of fins, n = 7
- The convection heat transfer coefficient of the finned and unfinned area = h.
- The efficiency of fins, ε = 0.9 ( 90% )
- The transformer fin base temperature, Tb = 60°C
- The free temperature of air, T∞ = 25°C
- The free stream velocity of air = U∞
Find:-
Determine the minimum free-stream velocity the fan needs to supply to avoid overheating. ( U∞ )
Solution:-
- Since the convection heat transfer coefficient of the finned and unfinned area i.e the fins and the transformer base are at the same temperature (Tb).
- The theoretical heat transfer ( Q_th ) rate from the fins can be calculated from the following convection cooling relation.
Q_th = h*As*[ Tb - T∞ ]
Where,
As : The total available surface area available for heat transfer.
Surface area of the fins (As1)As1 = n * { 2* [ ( l * h ) + ( t * h ) ] + ( l * t ) }
As1 = 7* { 2* [ ( 0.5 * 10 ) + ( 0.2 * 0.5 ) + ( 10 * 0.5 ) }
As1 = 106.4 cm^2 .... 0.01064 m^2
Surface area of the unfinned part of base (As2)As2 = Total base area - Finned top plane area
As2 = ( L * w ) - n* ( l * t ) = ( 10 * 6.2 ) - 7* ( 10 * 0.5 )
As2 = 27 cm^2 .... 0.0027 m^2
- Therefore, the total available surface area (As) is:
As = As1 + As2
As = 0.01064 + 0.0027
As = 0.01334 m^2
- The heat transfer coefficient (h) using convection heat transfer relation:
Q* ε = h*As*[ Tb - T∞ ]
h = Q* ε / [As*[ Tb - T∞ ] ]
h = (12*0.9) / [ 0.01334*( 60 - 25 ) ]
h = 23.13129 W/m^2K
- The air properties at film temperature:
T = 40 C
Viscosity ν = 1.6982 m^2 / s
Thermal conductivity, k = 0.027076 W/mK
Prandlt Number Pr = 0.71207
- The Nusselt number for the convection heat transfer for the transformer along the fins (Assumed flat plate):
Nu = h*L / k
Nu = 23.13129*0.1 / 0.027076
Nu = 85.43
- The correlation for Nusselt number between flow conditions and viscosity effects of the flow (Re & Pr) for a isothermal flat plate - Laminar Flow is given:
[tex]Nu = 0.664*Re^\frac{1}{2} *Pr^\frac{1}{3} \\\\Re^\frac{1}{2} = \frac{Nu}{0.664*Pr^\frac{1}{3}} \\\\\\Re = \sqrt{\frac{Nu}{0.664*Pr^\frac{1}{3}}} \\\\\\Re = \sqrt{\frac{85.43063}{0.664*0.71207^\frac{1}{3}}}\\\\Re = 12.00[/tex]
- The reynold number denotes the characteristic of the flow by the following relation:
Re = V∞*L / ν
V∞ = Re*ν / L
V∞ = 12*1.6982*10^-5 / 0.1
V∞ = 0.0020378 m/s .... = 2.0378 mm/s
Consider a refrigeration truck traveling at 55 mph at a location where the airtemperature is 80F. The refrigerated compartment of the truck can be considered to the a 9-ft-wide,8-ft-high, and 20-ft-long rectangular box. The refrigeration system of the truck removes heat at arate of 600 Btu/min. The outer surface of the truck is coated with a low-emissivity material, andthus radiation heat transfer is very small. Determine the averagetemperature of the outer surface ofthe refrigeration compartment of the truck. Assume the air flow over the entire outer surface to beturbulent, and the heat transfer coefficient at the front and rear surfaces to be equal to that on sidesurfaces.
The question is an engineering problem that involves calculating the average temperature of a truck's refrigeration compartment's outer surface. A precise answer would require additional thermal information and properties, which are not provided in the question.
Explanation:The question is related to the field of thermodynamics and heat transfer, specific to engineering. It requires determining the average temperature of the outer surface of the refrigeration compartment of a truck. However, to provide a precise answer, additional data would be required, including the thermal properties of the truck's material, the heat transfer coefficient, and the difference between the interior and exterior temperatures. Typically, such a problem would involve calculations using the concepts of convection and possibly conduction, considering the truck as a heat exchanger with heat being removed by the refrigeration system and added from the external environment. Without specific values for heat transfer coefficients and material properties, a calculation cannot be accurately made.
You are not changing the carrier signal, only the message. In the scope the center Page 5 of 6 frequency should remain at 14kHz, the frequency span at 20kHz and the dB/div at 15dB. Here are the AM signal in time domain and its frequency spectrum. Explain what you see. (Hint: Remember the Fourier analysis of the square wave performed in Lab #3.)
Answer:
We will see a waveform displayed on the screen and it will be PWM(pulse width modulation) of sinusoidal wave,this wave should have a frequency of 14KHz and it will form a vibration spectrum.
How does the resistance in the circuit impact the height and width of the resonance curve? (If the resistance were to increase would the height change? Would the width? If so, how?)
Answer:
The reactances vary with frequency, with large XL at high frequencies and large Xc at low frequencies, as we have seen in three previous examples. At some intermediate frequency fo, the reactances will be the same and will cancel, giving Z = R; this is a minimum value for impedance and a maximum value for Irms results. We can get an expression for fo by taking
XL=Xc
Substituting the definitions of XL and XC,
2[tex]\pi[/tex]foL=1/2[tex]\pi[/tex]foC
Solving this expression for fo yields
fo=1/2[tex]\pi[/tex][tex]\sqrt{LC}[/tex]
where fo is the resonant frequency of an RLC series circuit. This is also the natural frequency at which the circuit would oscillate if it were not driven by the voltage source. In fo, the effects of the inductor and capacitor are canceled, so that Z = R and Irms is a maximum.
Explanation:
Resonance in AC circuits is analogous to mechanical resonance, where resonance is defined as a forced oscillation, in this case, forced by the voltage source, at the natural frequency of the system. The receiver on a radio is an RLC circuit that oscillates best at its {f} 0. A variable capacitor is often used to adjust fo to receive a desired frequency and reject others is a graph of current versus frequency, illustrating a resonant peak at Irms at fo. The two arcs are for two dissimilar circuits, which vary only in the amount of resistance in them. The peak is lower and wider for the highest resistance circuit. Thus, the circuit of higher resistance does not resonate as strongly and would not be as selective in a radio receiver, for example.
A current versus frequency graph for two RLC series circuits that differ only in the amount of resistance. Both have resonance at fo, but for the highest resistance it is lower and wider. The conductive AC voltage source has a fixed amplitude Vo.
Consider a very long, slender rod. One end of the rod is attached to a base surface maintained at Tb, while the surface of the rod is exposed to an air temperature of 400°C. Thermocouples imbedded in the rod at locations 25 mm and 120 mm from the base surface register temperatures of 335°C and 375°C, respectively.
(a) Calculate the rod base temperature (°C).
(b) Determine the rod length (mm) for the case where the ratio of the heat transfer from a finite length fin to the heat transfer from a very long fin under the same conditions is 99 percent.
Answer:
(a) Calculate the rod base temperature (°C). = 299.86°C
(b) Determine the rod length (mm) for the case where the ratio of the heat transfer from a finite length fin to the heat transfer from a very long fin under the same conditions is 99 percent. = 0.4325m
Explanation:
see attached file below
A completely reversible heat pump produces heat at a rate of 100 kW to warm a house maintained at 25℃. The exterior air, which is at 0℃, serves as the source. Calculate the rate of entropy change of the two reservoirs and determine if this heat pump satisfies the second law according to the increase of entropy principle.
Answer:
1) 0. 03 kW/K
2) the value is grater than zero so it satisfies the second law of thermodynamic (states that rate of entropy change must be equal to or greater than zero) .
Explanation:
Rate of entropy change S = dQ/dT
= Q(1/T1 - 1/T2)
T2 = 25°C = 298 K
T1 = 0°C = 273 K
Q = 100 kW
S = 100( 1/273 - 1/298)
S = 100(0.0003) = 0. 03 kW/K
The density of a liquid is to be determined by an old 1-cm-diameter cylindrical hydrometer whose division marks are completely wiped out. The hydrometer is first dropped in water, and the water level is marked. The hydrometer is then dropped into the other liquid, and it is observed that the mark for water has risen 1.4 cm (hw) above the liquid–air interface. If the height of the original water mark is 23 cm (hl + hw), determine the density of the liquid.
Answer:
1064.8 kg/m³
Explanation:
Weight of the hydrometer = ρghA where ρ is the density, g is acceleration due to gravity, h is the submerged height and A is the cross sectional area.
W in water = ρwghwA
W in liquid = (ρliq)g hliq A where the cross sectional area is constant
W in water = W in liquid
(ρw)ghwA = (ρliq)g hliq A where ρw is density of water, ρliq is the density of liquid and hw and hliq are the heights of the liquid and that water. g acceleration due to gravity cancel on both sides as well as the constant A
pliq = [tex]\frac{hw}{hliq}[/tex] × 1000 kg /m³ ( density of water) =( [tex]\frac{23}{23-1.4}[/tex]) × 1000 = 1064.8 kg/m³
The diameter of an extruder barrel = 85 mm and its length = 2.00 m. The screw rotates at 55 rev/min, its channel depth = 8.0 mm, and its flight angle = 18°. Head pressure at the die end of the barrel = 10.0(10^6) Pa. Viscosity of the polymer melt = 100 Pa- s
(a) Find the volume flow rate of plastic at the die end of the barrel.
________ x 10^-6 m^3/s
Answer:
Qx = 9.10[tex]9.10^5 \times 10^{-6}[/tex] m³/s
Explanation:
given data
diameter = 85 mm
length = 2 m
depth = 9mm
N = 60 rev/min
pressure p = 11 × [tex]10^6[/tex] Pa
viscosity n = 100 Pas
angle = 18°
so Qd will be
Qd = 0.5 × π² ×D²×dc × sinA × cosA ..............1
put here value and we get
Qd = 0.5 × π² × ( 85 [tex]\times 10^{-3}[/tex] )²× 9 [tex]\times 10^{-3}[/tex] × sin18 × cos18
Qd = 94.305 × [tex]10^{-6}[/tex] m³/s
and
Qb = p × π × D × dc³ × sin²A ÷ 12 × n × L ............2
Qb = 11 × [tex]10^{6}[/tex] × π × 85 [tex]\times 10^{-3}[/tex] × ( 9 [tex]\times 10^{-3}[/tex] )³ × sin²18 ÷ 12 × 100 × 2
Qb = 85.2 × [tex]10^{-6}[/tex] m³/s
so here
volume flow rate Qx = Qd - Qb ..............3
Qx = 94.305 × [tex]10^{-6}[/tex] - 85.2 × [tex]10^{-6}[/tex]
Qx = 9.10[tex]9.10^5 \times 10^{-6}[/tex] m³/s
1. A spur gear made of bronze drives a mid steel pinion with angular velocity ratio of 13 /2 : 1. Thepressure angle is 14 1/2° . It transmits 5 kW at 1800 r.p.m. of pinion. Considering only strength, design the smallest diameter gears and find also necessary face width. The number of teeth should not be less than 15 teeth on either gear. The elastic strength of bronze may be taken as 84 MPa and of steel as 105 MPa. Lewis factor for 14 1/2° pressure angle may be taken as y =0.6840.124 –No. of teeth.
Answer:
Given data
w1/w2=6.5/1
Power=5 KW
wp=1800 rpm
angle=14 degrees
Based on above values,the minimum diameter=30 mm
A pipe 300 m long has a slope of 1 in 100 and tapers from 1.2 m diameter at the high end to 0.6 m diameter at the low end. Quantity of water flowing is 5400 liters per minute. If the pressure at the high end is 68.67 kPa, find the pressure at the low end. Neglect head loss.
Answer:
P = 98052.64 Pa or 98.05 kPa
Explanation:
Using Bernoulli's equation;
P+rho*v^2/2+ rho*g*z = constant
at high end;
dia= 1.2 m
flow, Q = 5400 L/min = 0.09 m^3/s
therefore, velocity at the high end, v1 = Q/A =0.09/(pi()*(1.2/2)^2) = 0.08 m/s
pressure, P = 68.67 kPa
Solving for elevation, z
assume lower end is reference line. then higher end will be 'x' m high wrt to lower end.
x= 300*sin(tan^-1(1/100)) = 3 m
that means higher end will be 3 m above with respect to lower end
Similarly for lower end;
dia= 0.6 m
flow, Q = 5400 L/min = 0.09 m^3/s
therefore, velocity at the high end, v2 = Q/A =0.09/(pi()*(0.6/2)^2) = 0.318 m/s
assume pressure, P
z=0
put all values in the formula, we get;
68.67*10^3+1000*0.08^2/2+ 1000*9.81*3 =P+1000*0.318^2/2+ 0
solving this, we get;
P = 98052.64 Pa or 98.05 kPa
According to Bernoulli's principle, a lower pressure than expected at the
lower end because the velocity of the fluid is higher.
The pressure at the low end is approximately 97.964 kPa.Reasons:The given parameter are;
Length of the pipe, L = 300 m
Slope of the pipe = 1 in 100
Diameter at the high end, d₁ = 1.2 m
Diameter at the low end, d₂ = 0.6 m
The volume flowrate, Q = 5,400 L/min
Pressure at the high end, P = 68.67 kPa
Required:Pressure at the low end
Solution:The elevation of the pipe, z₁ = [tex]300 \, m \times \frac{1}{100} = 3 \, m[/tex]
z₂ = 0
The continuity equation is given as follows;
Q = A₁·v₁ = A₂·v₂
[tex]\sqrt[n]{x} \displaystyle Q = 5,400 \, L/min = 5,400 \, \frac{L}{min} \times \frac{1 \, m^3}{1,000 \, L} \times \frac{1 \, min}{60 \, seconds} = \mathbf{ 0.09 \, m^3/s}[/tex]
Therefore;
[tex]\displaystyle 0.09 = \frac{\pi}{4} \times 1.2^2 \times v_1 = \mathbf{\frac{\pi}{4} \times 0.6^2 \times v_2}[/tex]
[tex]\displaystyle v_1 = \frac{0.09}{\frac{\pi}{4} \times 1.2^2 } \approx 0.0796[/tex]
[tex]\displaystyle v_2 =\frac{0.09}{\frac{\pi}{4} \times 0.6^2 } \approx \mathbf{0.318}[/tex]
The Bernoulli's equation is given as follows;[tex]\displaystyle \frac{p_1}{\rho \cdot g} + \frac{v_1^2}{2 \cdot g} + z_1 = \mathbf{ \frac{p_2}{\rho \cdot g} + \frac{v_2^2}{2 \cdpt g} + z_2}[/tex]
Therefore;
[tex]\displaystyle p_2 = \left(\frac{p_1}{\rho \cdot g} + \frac{v_1^2}{2 \cdot g} + z_1 - \left( \frac{v_2^2}{2 \cdot g} + z_2 \right)\right) \times \rho \cdot g = p_1 + \frac{\rho}{2} \cdot \left(v_1^2} -v_2^2 \right)+ \rho \cdot g \left(z_1 - z_2\right)[/tex]
The density of water, ρ = 997 kg/m³
Which gives;
[tex]\displaystyle p_2 = 68670 + \frac{997 }{2} \times \left(0.0796^2- 0.318^2 \right) + 997 \times 9.81 \times \left( 3 - 0 \right) \approx \mathbf{97,964.46}[/tex]The pressure at the low end, p₂ ≈ 97,964.46 Pa ≈ 97.964 kPaLearn more about Bernoulli's principle here:
https://brainly.com/question/6207420
A solenoid with a length of 20 cm and a radius of 5 cm consists of 400 turns and carries a current of 12 A. If z = 0 represents the midpoint of the solenoid, generate a plot for |H(z)| along the axis of the solenoid for a range −20 cm ≤ z ≤ 20 cm. Please use MATLAB to generate the solution numerically and indicate how you did it. Include a copy of the computer code that you create to solve the problem
Answer:
Copy MATLAB code to plot the magnitude of magnetic field strength with respect to z on the axis of solenoid:
z=-20:0.01:20;
H=120.*(((20-(2.*z))./sqrt((20-(2.*z)).^2+100))+((20+(2.*z))./sqrt((20+(2.*z)).^2+100)));
plot(z,H)
title('plot of |H| vs z along the axis of solenoid')
ylabel('Magnitude of magnetic field 'H")
xlabel('position on axis of solenoid 'z")
Explanation:
full explanation is attached as picture and the resultant plot also.
Evaporation in Double-Effect Reverse-Feed Evaporators. A feed containing 2 wt % dissolved organic solids in water is fed to a double-effect evaporator with reverse feed. The feed enters at 100°F and is concentrated to 25% solids. The boiling-point rise can be considered negligible as well as the heat of solution. Each evaporator has a 1000-ft2 surface area and the heat-transfer 700 btu/h -ft2-°F. The feed enters evaporator number 2 and steam at 100 psia is fed to number 1. The pressure iin the vapor space of evaporator number 2 is 0.98 psia. Assume that the heat capacity of all liquid solutions is that of liquid water. Calculate the feed rate F and the product rate Li of a solution containing 25% solids. (Hint: Assume a feed rate of, say, F 1000 lbm/h. Calculate the area. Then calculate the actual coefficients are U1 500 and U2- feed rate by multiplying 1000 by 1000/calculated area.) Ans. F- 133 800 lbm/h (60 691 kg/h), L,- 10700lb»/h (4853 kg/h)
Answer:
472,826 lb/hr
Explanation:
As per the given data:
Solids in feed= 2%
Solids in concentrate= 25%
HTA1 = HTA2 = 1000 ft^2
U1 = 500 Btu/ h ft^2 F & U2 = 700 Btu/ h ft^2 F
Overall material balance: Feed= Distillate + concentrate ----> Eq-1
Component balance: Feed * 0.02 = Distillate * 0 + concentrate * 0.25
Feed = 12.5 * concentrate ---> Eq-2
Boiling point rise = negligible, so solution & solvent vapor temperature will be same.
Assumed that the 1st effect is operating under atmospheric pressure (Boiling point - 212F).
As per the data:
Latent heat 212F = 300 Btu/lb
Latent heat 100F = 320 Btu/lb
As per material balance:
Vapor flowrate * latent heat = Overall HT coefficient * HTA * DT
1st effect: M-1= (500 * 1000 * (326-212)) / 300 = 190,000 lb/hr
2nd effect: M-2= (700*1000 * (212-100)) / 320 = 245,000 lb/hr
Distillate = M-1 + M-2 = 190,000+245,000 = 435,000 lb/hr
Substituting the above in Eq-1
Feed = 435,000 + concentrate
Substitute Eq-2 in the above
12.5 * concentrate = 435,000 + concentrate
Concentrate, L1 = 435,000/11.5 = 37826 lb /hr
Feed, F = 435,000 + 37826 = 472,826 lb/hr
1st effect operating pressure is not given, That may be the reason we are not getting the given answer. But procedure is right.
[ Find the figure in the attachment ]
A turbine operates at steady state, and experiences a heat loss. 1.1 kg/s of water flows through the system. The inlet is maintained at 100 bar, 520 Celsius. The outlet is maintained at 10 bar, 280 Celsius. A rate of heat loss of 60 kW is measured. Determine the rate of work output from the turbine, in kW.
Answer:
[tex]\dot W_{out} = 399.47\,kW[/tex]
Explanation:
The turbine is modelled after the First Law of Thermodynamics:
[tex]-\dot Q_{out} -\dot W_{out} + \dot m\cdot (h_{in}-h_{out}) = 0[/tex]
The work done by the turbine is:
[tex]\dot W_{out} = \dot m \cdot (h_{in}-h_{out})-\dot Q_{out}[/tex]
The properties of the water are obtained from property tables:
Inlet (Superheated Steam)
[tex]P = 10\,MPa[/tex]
[tex]T = 520\,^{\textdegree}C[/tex]
[tex]h = 3425.9\,\frac{kJ}{kg}[/tex]
Outlet (Superheated Steam)
[tex]P = 1\,MPa[/tex]
[tex]T = 280\,^{\textdegree}C[/tex]
[tex]h = 3008.2\,\frac{kJ}{kg}[/tex]
The work output is:
[tex]\dot W_{out} = \left(1.1\,\frac{kg}{s}\right)\cdot \left(3425.9\,\frac{kJ}{kg} -3008.2\,\frac{kJ}{kg}\right) - 60\,kW[/tex]
[tex]\dot W_{out} = 399.47\,kW[/tex]
5/25 At the instant under consideration, the hydraulic cylinder AB has a length L = 0.75 m, and this length is momentarily increasing at a constant rate of 0.2 m/s. If vA = 0.6 m/s and θ = 35°, determine the velocity of slider B.
The image of the question is missing, so i have attached it
Answer:
Velocity of slider B; = - 0.176 m/s
Explanation:
We are given;
Length of (AB) = 0.75 m
Rate of increase of length; (AB)' = 0.2 m/s
vA = 0.6 m/s
θ = 35°
We want to find vB;
Looking at the image attached, we can use the trigonometric ratio to find OA
Thus;
Sin θ = (OA)/(AB)
So, Sin 35° = (OA)/(AB)
(OA) = (AB)Sin 35°
(OA) = 0.75•Sin 35°
(OA) = 0.75•0.5736
(OA) = 0.43 m
Also, we can use the same system to find (OB)
Thus;
Cos θ = (OB)/(AB)
Cos 35° = (OB)/(AB)
(OB) = (AB)Cos 35°
(OB) = 0.75•Cos 35°
(OB) = 0.75•0.8192
(OB) = 0.6144 m
We apply Pythagoras' theorem as follows
(AB)² = (OA)² + (OB)²
We derive the equation;
2*(AB)*(AB)' = 2*(OA)*vA + 2*(OB)*vB
Divide through by 2 to give;
(AB)*(AB)' = (OA)*vA + (OB)*vB
vB = ((AB)*(AB)' - (OA)*vA) / (OB)
We now have ;
vB = ((0.75 m)*(0.2 m/s) - (0.43 m)*(0.6 m/s)/(0.614 m)
vB = - 0.176 m/s
The attached program (studentsGpa.cpp) uses dynamic allocation to create an array of strings. It asks the user to enter a number and based on the entered number it allocates the array size. Then based on that number it asks the user that many times to enter student’s names. What you need to do:Add another array of doubles to store the gpa of each student as you enter themYou need to display both the student’s name and the gpa.NOTE: must use pointer notation not array subscript. Any submission that uses array subscript won’t be graded
Question: The program was not attached to your question. Find attached of the program and the answer.
Answer:
See the explanation for the answer.
Explanation:
#include <iostream>
using namespace std;
int main()
{
cout << "How many students will you enter? ";
int n;
cin>>n;
string *name = new string[n];
double *gpa = new double[n];
for(int i=0;i<n;i++){
cout<<"Enter student"<<(i+1)<<"'s name: ";
cin>>name[i];
cout<<"Enter student"<<(i+1)<<"'s gpa: ";
cin>>gpa[i];
}
cout<<"The list students"<<endl;
cout<<"Name GPA"<<endl;
cout<<"----------------------"<<endl;
for(int i=0;i<n;i++){
cout<<name[i]<<" "<<gpa[i]<<endl;
}
return 0;
}
OUTPUT : See the attached file.
5. Steel balls 50 mm in diameter are annealed by heating to 1200 K and then slowly cooling to 450 K in an air environment for which the ambient temperature is 300 K and h = 20 W/m2 ·K. Assuming the properties of the steel to be k = 40 W/m·K, rho = 7800 kg/m3 , and c = 600 J/kg·K. Estimate the time required for this cooling process.
Answer:
time required for cooling process = 0.233 hours
Explanation:
In Transient heat conduction of a Sphere, the formula for Biot number is;
Bi = hL_c/k
Where L_c = radius/3
We are given;
Diameter = 12mm = 0.012m
Radius = 0.006m
h = 20 W/m²
k = 40 W/m·K
So L_c = 0.006m/3 = 0.002m
So,Bi = 20 x 0.002/40
Bi = 0.001
The formula for time required is given as;
t = (ρVc/hA)•In[(T_i - T_(∞))/(T - T_(∞))]
Where;
A is Area = πD²
V is volume = πD³/6
So,
t = (ρ(πD³/6)c/h(πD²))•In[(T_i - T_(∞))/(T - T_(∞))]
t = (ρDc/6h)•In[(T_i - T_(∞))/(T - T_(∞))]
We are given;
T_i = 1200K
T_(∞) = 300K
T = 450K
ρ = 7800 kg/m³
c = 600 J/kg·K
Thus, plugging in relevant values;
t = (7800 x 0.012 x 600/(6 x20) )•In[(1200 - 300)/(450 - 300)]
t = 468•In6
t = 838.54 seconds
Converting to hours,
t = 838.54/3600
t = 0.233 hours
• Build upon the results of problem 3-85 to determine the minimum factor of safety for fatigue based on infinite life, using the modified : Goodman criterion. The shaft CD rotates at a constant speed, has a constant diameter of 1.13 in, and is made from cold-drawn AISI 1018 steel. From problem 3-85, the critical stress element in shaft CD experiences a completely reversed bending stress due to the rotation, as well as steady torsional and axial stresses. Thus, a,bend= 12 kpsi, Om, bend= 0 kpsi, Oa,axial= 0 kpsi, om, axial= -0.9 kpsi, Ta = 0 kpsi, and Im = 10 kpsi. The minimum factor of safety for fatigue is
Answer:
minimum factor of safety for fatigue is = 1.5432
Explanation:
given data
AISI 1018 steel cold drawn as table
ultimate strength Sut = 63.800 kpsi
yield strength Syt = 53.700 kpsi
modulus of elasticity E = 29.700 kpsi
we get here
[tex]\sigma a[/tex] = [tex]\sqrt{(\sigma a \times kb)^2+3\times (za\times kt)^2}[/tex] ...........1
here kb and kt = 1 combined bending and torsion fatigue factor
put here value and we get
[tex]\sigma a[/tex] = [tex]\sqrt{(12 \times 1)^2+3\times (0\times 1)^2}[/tex]
[tex]\sigma a[/tex] = 12 kpsi
and
[tex]\sigma m[/tex] = [tex]\sqrt{(\sigma m \times kb)^2+3\times (zm\times kt)^2}[/tex] ...........2
put here value and we get
[tex]\sigma m[/tex] = [tex]\sqrt{(-0.9 \times 1)^2+3\times (10\times 1)^2}[/tex]
[tex]\sigma m[/tex] = 17.34 kpsi
now we apply here goodman line equation here that is
[tex]\frac{\sigma m}{Sut} + \frac{\sigma a}{Se} = \frac{1}{FOS}[/tex] ...................3
here Se = 0.5 × Sut
Se = 0.5 × 63.800 = 31.9 kspi
put value in equation 3 we get
[tex]\frac{17.34}{63.800} + \frac{12}{31.9} = \frac{1}{FOS}[/tex]
solve it we get
FOS = 1.5432
The intercept of the CML is the origin while the intercept of the SML is RF CML consists of efficient portfolios, while the SML is concerned with all portfolios or securities CML could be downward sloping while that is impossible for the SML CML and the SML are essentially the same except in terms of the securities represented
Answer:
Here, The CML is used for efficient portfolios whereas the SML applies to all portfolios or securities
Considering the seperation theorem, The separation theorem states that the investment decision is sepaarte from the financing decision.
This implies that The SML can be used to analyze the relationship between risk and requried return for all assets.
Under the separation theorem investors should Hold the same portfolio of risky assets and the same expected return but at different levels of risk
Explanation:
See answer
"A northbound freeway segment is on a 4% upgrade from station 430+20 to 450+00 and has two 11-ft wide lanes, a 5-ft right shoulder, and has a ramp density of 1 per mile in the 3 miles before and after station 440+10. The peak-hour factor is 0.9. Northbound traffic during the peak hour is 2550 cars, 300 STs, and 300 TTs. Determine the density and LOS of the freeway segment."
Answer: D = 23.09 pc/mi/h
LOS = C
Explanation:
we will begin by solving this with a step by step process for easy understanding;
given that the freeway has two lanes = 11 ft wide
and has a width of 5 ft right shoulder.
ramp density = 1 per mile in 3m
substituting the free flow speed value gives us;
Free flow speed = 75 - 1.9 - 0.6 - (3.22 × 1∧0.84) = 69.28 mph
we have that the length of the road = (1980 ft) × (1 mile / 5280 ft)
L = 0.375 mile
The next thing we will do is to calculate the proportion of bus and the truck
Pt = 300 + 300 / (2400 + 300 + 300)
Pt = 600/3000 = 20%
following up, we will consider the length and percentage of the buses and the trucks
Et = 2.0, Pr = 0, Er = 0
to calculate the percentage of truck
Ft = 1 / 1 + Pt (Et -1 ) + Pr (Er -1)
Ft = 1 / 1+0.2 (2-1) + 0 = 0.833
Truck percentage = 0.833
To the determine the traffic volume,
Vt = V / PHF × N × Ft × Fp
Vt = 2400/ (0.9×2×0.833×1) = 1600 pc/lane/hour
But the Density of the freeway is given thus;
D = Vp / FFS .............(1)
but to get the FFS, we will consider the graph of flow rate vs speed and show the level of service
FFS = 69.28 mi/h
From the above expression in (1) we have that
D = 1600/69.28 = 23.09 pc/mi/h
D = 23.09 pc/mi/h
now we have that the the density of the freeway segment is 23.09 pc/mi/h, we can thus safely say that the level of service (los) = C
cheers i hope this helps
Air is cooled and dehumidified as it flows over the coils of refrigeration system at 100 kPa from 30 ºC and relative humidityof 84%to 15 ºC and relative humidity of 100%. The mass flow rate of dry air is 0.4 kg/s.
Using the formulaand not the Psychrometric chart, determine:
a) the mass flow rate of water,
b)the heat removal from the air.
Answer:
(a) The mass glow rate of water is 0.0032kg/s
(b) The heat removal from air is 14.17KJ/sec
Explanation:
In this question, we are asked to use the formula to calculate the mass flow rate and the heat removal from water based on the data in the question.
To answer this question, we take values of absolute humidity and enthalpy values from table from corresponding temperature
Please check attachment for complete solution and step by step explanation
Two monitoring wells were constructed in an unconfined aquifer. The wells are separated by a distance of 250 ft. The water surface elevations in the up-gradient and down-gradient wells were 101.00 ft and 100.85 ft, respectively. The aquifer hydraulic conductivity is 5 ft/day. The fluid velocity (ft/day) in the aquifer is most nearly:
Answer:
0.003
Explanation:
? → ? = −??ℎ??→ ?
= ??ℎ??? = ?ℎ2− ℎ1∆?→ ? = 5????.101 ?? − 100.85 ??250 ??= 0.003???
A 2-lane highway is to be constructed across a 6-ft diameter metal culvert which is oriented perpendicular to the highway center line. The culvert is located at station 33+00, and the invert (bottom) of the culvert has an elevation of 150 ft. The elevation of station 21+00 on the tangent alignment is 140 ft. The alignment gradient is +4.0% from station 21+00 to station 29+00, and the gradient from station 29+00 to 37+00 is -3%.
a. Find the longest full station vertical curve that will give approximately 3 ft (3 plusminus 0.5 ft) of cover over the top of the culvert.
b. Compute the station and elevation of the PVC and PVT and the elevation of each full station on the vertical curve.
Answer:
Dude just like forget the highway and drive on the interstate bruh
Explanation:
For the following transfer function, derive expressions for the real and imaginary part for s = jω in terms of the frequency variable ω. Then write a MATLAB script to plot the imaginary part versus the real part (and its reflection about the real axis) for a frequency ω range of 10−2 to 102 radians per second. Verify that your plots match the output of the nyquist function in MATLAB. • G(s) = 1 /(s+0.5)(s+1)(s+2) Suppose G represents an open-loop plant transfer function. Use your plot to determine the Gain Margin for the closed-loop system, i.e., determine how much the loop gain could be increased before the closed-loop becomes unstable
Answer:
See all solutions attached as picture.
Explanation:
It is well explanatory
One method of reducing an aircarft’s landing distance is through the use of thrust reversers. Consider the turbofan engine in Fig. P2.5 with thrust reverser of the bypass airstream. It is given that 1500 lbm / s of air at 60 8 F and 14.7 psia enters the engine at a velocity of 450 ft / s and that 1250 lbm / s of bypass air leaves the engine at 60 deg to the horizontal, velocity of 890ft / s, and pressure of 14.7 psia. The remaining 250 lbm / s leaves the engine core at a velocity of 1200 fps and a pressure of 14.7 psia.
Determine the force on the strut [Fx]. Assume the outside of the engine sees a pressure of 14.7 psia.
Answer:
The force on the strut is 909000 lbm ft/s²
Explanation:
please look at the solution in the attached Word file