Answer:
At L = 0.1 m
h⁻_lam = 11.004K W/m^1.5
h⁻_turb = 7.8848K W/m^1.8
At L = 1 m
h⁻_lam = 3.48K W/m^1.5
h⁻_turb = 4.975K W/m^1.8
Explanation:
Given that;
h_lam(x)= 1.74 W/m^1.5. Kx^-0.5
h_turb(x)= 3.98 W/m^1.8 Kx^-0.2
conditions for plates of length L = 0.1 m and 1 m
Now
Average heat transfer coefficient is expressed as;
h⁻ = 1/L ₀∫^L hxdx
so for Laminar flow
h_lam(x)= 1.74 . Kx^-0.5 W/m^1.5
from the expression
h⁻_lam = 1/L ₀∫^L 1.74 . Kx^-0.5 dx
= 1.74k / L { [x^(-0.5+1)] / [-0.5 + 1 ]}₀^L
= 1.74k/L = [ (x^0.5)/0.5)]⁰^L
= 1.74K × L^0.5 / L × 0.5
h⁻_lam= 3.48KL^-0.5
For turbulent flow
h_turb(x)= 3.98. Kx^-0.2 W/m^1.8
form the expression
1/L ₀∫^L 3.98 . Kx^-0.2 dx
= 3.98k / L { [x^(-0.2+1)] / [-0.2 + 1 ]}₀^L
= (3.98K/L) × (L^0.8 / 0.8)
h⁻_turb = 4.975KL^-0.2
Now at L = 0.1 m
h⁻_lam = 3.48KL^-0.5 = 3.48K(0.1)^-0.5 W/m^1.5
h⁻_lam = 11.004K W/m^1.5
h⁻_turb = 4.975KL^-0.2 = 4.975K(0.1)^-0.2
h⁻_turb = 7.8848K W/m^1.8
At L = 1 m
h⁻_lam = 3.48KL^-0.5 = 3.48K(1)^-0.5 W/m^1.5
h⁻_lam = 3.48K W/m^1.5
h⁻_turb = 4.975KL^-0.2 = 4.975K(1)^-0.2
h⁻_turb = 4.975K W/m^1.8
Therefore
At L = 0.1 m
h⁻_lam = 11.004K W/m^1.5
h⁻_turb = 7.8848K W/m^1.8
At L = 1 m
h⁻_lam = 3.48K W/m^1.5
h⁻_turb = 4.975K W/m^1.8
Products exit a combustor at a rate of 100 kg/sec, and the air-fuel ratio is 9. Determine the air flow rate. a. 9 kg/sec b. 90 kg/sec c. 100 kg/sec d. 10 kg/sec
Answer: the air flow rate a is 90 kg/sec; Option b) 90 kg/sec is the correct answer
Explanation:
Given that;
product of combustor flow rate m = 100 kg/s
air-fuel = 9
Airflow rate = ?
⇒We know that in the combustor, air fuel are mixed and then ignited,
⇒air fuel products are exited at the combustor
let air and fuel be a and b respectively
⇒ a + b = 100 kg/sec ----- let this be equation 1
now
⇒ air / fuel = 9
a / b = 9
a = 9b -----------let this be equation 2
now input a = 9b in equation 1
9b + b = 100 kg/sec
10b = 100 kg/sec
b = 10 kg/sec
we know that
a = 9b
so a = 9 × 10 = 90 kg/sec
Therefore the air flow rate a is 90 kg/sec
Air is compressed by a 30-kW compressor from P1 to P2. The air temperature is maintained constant at 25°C during this process as a result of heat transfer to the surrounding medium at 20°C. Determine the rate of entropy change of the air.
Answer:
-0.1006Kw/K
Explanation:
The rate of entropy change in the air can be reduced from the heat transfer and the air temperature. Hence,
ΔS = Q/T
Where T is the constant absolute temperature of the system and Q is the heat transfer for the internally reversible process.
S(air) = - Q/T(air) .......1
Where S.air =
Q = 30-kW
T.air = 298k
Substitute the values into equation 1
S(air) = - 30/298
= -0.1006Kw/K
A single phase inductive load draws 10 MW at 0.6 power factor lagging. Draw the power triangle and determine the reactive power of a capacitor to be connected in parallel with the load to raise the power factor to 0.85.
Answer: attached below is the power triangles
7.13589 MVAR
Explanation:
Power ( P1 ) = 10 MW
power factor ( cos ∅ ) = 0.6 lagging
New power factor = 0.85
Calculate the reactive power of a capacitor to be connected in parallel
Cos ∅ = 0.6
therefore ∅ = 53.13°
S = P1 / cos ∅ = 16.67 MVA
Q1 = S ( sin ∅ ) = 13.33 MVAR ( reactive power before capacitor was connected in parallel )
note : the connection of a capacitor in parallel will cause a change in power factor and reactive power while the active power will be unchanged i.e. p1 = p2
cos ∅2 = 0.85 ( new power factor )
hence ∅2 = 31.78°
Qsh ( reactive power when power factor is raised to 0.85 )
= P1 ( tan∅1 - tan∅2 )
= 10 ( 1.333 - 0.6197 )
= 7.13589 MVAR
A stream leaving a sewage pond (containing 80 mg/L of sewage) moves as a plug with a velocity of 40 m/hr. A concentration of 50 mg/L is measured 5,000 m downstream. What is the 1st order decay rate constant in the stream?
Answer:Decay rate constant,k = 0.00376/hr
Explanation:
IsT Order Rate of reaction is given as
In At/ Ao = -Kt
where [A]t is the final concentration at time t and [A]o is the inital concentration at time 0, and k is the first-order rate constant.
Initial concentration = 80 mg/L
Final concentration = 50 mg/L
Velocity = 40 m/hr
Distance= 5000 m
Time taken = Distance / Time
5000m / 40m/hr = 125 hr
In At/ Ao = -Kt
In 50/80 = -Kt
-0.47 = -kt
- K= -0.47 / 125
k = 0.00376
Decay rate constant,k = 0.00376/hr
please help me make a lesson plan. the topic is Zigzag line. and heres the format.
A. Objective
B. Subject matter
C. Learning activities.
D. Assessment.
E. Reinforcement
Explanation:
D. B. C. A. E. Is this a good idea
Help this is very hard and I don't get it
Answer:
yes it is very hard you should find a reccomended doctor to aid in your situation. But in the meantime how about you give me that lil brainliest thingy :p
In a CS amplifier, the resistance of the signal source Rsig = 100 kQ, amplifier input resistance (which is due to the biasing network) Rin = 100kQ, Cgs = 1 pF, Cgd = 0.2 pF, gm = 5 mA/V, ro = 25 kΩ, and RL = 20 kΩ. Determine the expected 3-dB cutoff frequency.
Answer:
406.140 KHz
Explanation:
Given data:
Rsig = 100 kΩ
Rin = 100kΩ
Cgs = 1 pF,
Cgd = 0.2 pF, and etc.
Determine the expected 3-dB cutoff frequency
first find the CM miller capacitance
CM = ( 1 + gm*ro || RL )( Cgd )
= ( 1 + 5*10^-3 * 25 || 20 ) ( 0.2 )
= ( 11.311 ) pF
now we apply open time constant method to determine the cutoff frequency
Th = 1 / Fh
hence : Fh = 1 / Th = [tex]\frac{1}{(Rsig +Rin) (Cm + Cgs )}[/tex]
= [tex]\frac{1}{( 200*10^3 ) ( 12.311 * 10^{-12} )}[/tex] = 406.140 KHz
Calculate the LER for the rectangular wing from the previous question if the weight of the glider is 0.0500 Newton’s.
Answer:
0.2
Explanation:
Since the span and chord of the rectangular wing is missing, due to it being from the other question, permit me to improvise, or assume them. While you go ahead and substitute the ones from your question to it, as it's both basically the same method.
Let the span of the rectangular wing be 0.225 m
Let the chord of the rectangular wing be 0.045 m.
Then, the area of any rectangular chord is
A = chord * span
A = 0.045 * 0.225
A = 0.010 m²
And using the weight of the glider given to us from the question, we can find the LER for the wing.
LER = Area / weight.
LER = 0.010 / 0.05
LER = 0.2.
Therefore, using the values of the rectangular wing I adopted, and the weight of the glider given, we can see that the LER of the glider is 0.2
Please mark brainliest...
Answer: 0.2025
Explanation: I got it correct
A 13.7g sample of a compound exerts a pressure of 2.01atm in a 0.750L flask at 399K. What is the molar mass of the compound?a. 318 g/mol
b. 204 g/mol
c. 175 g/mol
d. 298 g/mol
Answer: Option D) 298 g/mol is the correct answer
Explanation:
Given that;
Mass of sample m = 13.7 g
pressure P = 2.01 atm
Volume V = 0.750 L
Temperature T = 399 K
Now taking a look at the ideal gas equation
PV = nRT
we solve for n
n = PV/RT
now we substitute
n = (2.01 atm x 0.750 L) / (0.0821 L-atm/mol-K x 399 K )
= 1.5075 / 32.7579
= 0.04601 mol
we know that
molar mass of the compound = mass / moles
so
Molar Mass = 13.7 g / 0.04601 mol
= 297.7 g/mol ≈ 298 g/mol
Therefore Option D) 298 g/mol is the correct answer