Answer:
15.64 MW
Explanation:
The computation of value of X that gives maximum profit is shown below:-
Profit = Revenue - Cost
= 15x - 0.2x 2 - 12 - 0.3x - 0.27x 2
= 14.7x - .47x^2 - 12
After solving the above equation we will get maximum differentiate for profit that is
14.7 - 0.94x = 0
So,
x = 15.64 MW
Therefore for computing the value of X that gives maximum profit we simply solve the above equation.
Only put ciilant into ur radiator when the engine is cool (D)
Answer:
a) V = 0.354
b) G = 25.34 GPA
Explanation:
Solution:
We first determine Modulus of Elasticity and Modulus of rigidity
Elongation of rod ΔL = 1.4 mm
Normal stress, δ = P/A
Where P = Force acting on the cross-section
A = Area of the cross-section
Using Area, A = π/4 · d²
= π/4 · (0.0020)² = 3.14 × 10⁻⁴m²
δ = 50/3.14 × 10⁻⁴ = 159.155 MPA
E(long) = Δl/l = 1.4/600 = 2.33 × 10⁻³mm/mm
Modulus of Elasticity Е = δ/ε
= 159.155 × 10⁶/2.33 × 10⁻³ = 68.306 GPA
Also final diameter d(f) = 19.9837 mm
Initial diameter d(i) = 20 mm
Poisson said that V = Е(elasticity)/Е(long)
= - <u>( 19.9837 - 20 /20)</u>
2.33 × 10⁻³
= 0.354,
∴ v = 0.354
Also G = Е/2. (1+V)
= 68.306 × 10⁹/ 2.(1+ 0.354)
= 25.34 GPA
⇒ G = 25.34 GPA
Answer:
the overall heat transfer coefficient of this heat exchanger is 1855.8923 W/m²°C
Explanation:
Given:
d₁ = diameter of the tube = 1 cm = 0.01 m
d₂ = diameter of the shell = 2.5 cm = 0.025 m
Refrigerant-134a
20°C is the temperature of water
h₁ = convection heat transfer coefficient = 4100 W/m² K
Water flows at a rate of 0.3 kg/s
Question: Determine the overall heat transfer coefficient of this heat exchanger, Q = ?
First at all, you need to get the properties of water at 20°C in tables:
k = 0.598 W/m°C
v = 1.004x10⁻⁶m²/s
Pr = 7.01
ρ = 998 kg/m³
Now, you need to calculate the velocity of the water that flows through the shell:
![v_{w} =\frac{m}{\rho \pi (\frac{d_{2}^{2}-d_{1}^{2} }{4} )} =\frac{0.3}{998*\pi (\frac{0.025^{2}-0.01^{2} }{4}) } =0.729m/s](https://tex.z-dn.net/?f=v_%7Bw%7D%20%3D%5Cfrac%7Bm%7D%7B%5Crho%20%5Cpi%20%28%5Cfrac%7Bd_%7B2%7D%5E%7B2%7D-d_%7B1%7D%5E%7B2%7D%20%20%7D%7B4%7D%20%29%7D%20%3D%5Cfrac%7B0.3%7D%7B998%2A%5Cpi%20%28%5Cfrac%7B0.025%5E%7B2%7D-0.01%5E%7B2%7D%20%20%7D%7B4%7D%29%20%7D%20%3D0.729m%2Fs)
It is necessary to get the Reynold's number:
![Re=\frac{v_{w}(d_{2}-d_{1}) }{v} =\frac{0.729*(0.025-0.01)}{1.004x10^{-6} } =10891.4343](https://tex.z-dn.net/?f=Re%3D%5Cfrac%7Bv_%7Bw%7D%28d_%7B2%7D-d_%7B1%7D%29%20%7D%7Bv%7D%20%3D%5Cfrac%7B0.729%2A%280.025-0.01%29%7D%7B1.004x10%5E%7B-6%7D%20%7D%20%3D10891.4343)
Like the Reynold's number is greater than 10000, the regime is turbulent. Now, the Nusselt's number:
![Nu=0.023Re^{0.8} Pr^{0.4} =0.023*(10891.4343)^{0.8} *(7.01)^{0.4} =85.0517](https://tex.z-dn.net/?f=Nu%3D0.023Re%5E%7B0.8%7D%20Pr%5E%7B0.4%7D%20%3D0.023%2A%2810891.4343%29%5E%7B0.8%7D%20%2A%287.01%29%5E%7B0.4%7D%20%3D85.0517)
The overall heat transfer coefficient:
![Q=\frac{1}{\frac{1}{h_{1} }+\frac{1}{h_{2} } }](https://tex.z-dn.net/?f=Q%3D%5Cfrac%7B1%7D%7B%5Cfrac%7B1%7D%7Bh_%7B1%7D%20%7D%2B%5Cfrac%7B1%7D%7Bh_%7B2%7D%20%7D%20%20%7D)
Here
![h_{2} =\frac{kNu}{d_{2}-d_{1}} =\frac{0.598*85.0517}{0.025-0.01} =3390.7278W/m^{2}C](https://tex.z-dn.net/?f=h_%7B2%7D%20%3D%5Cfrac%7BkNu%7D%7Bd_%7B2%7D-d_%7B1%7D%7D%20%3D%5Cfrac%7B0.598%2A85.0517%7D%7B0.025-0.01%7D%20%3D3390.7278W%2Fm%5E%7B2%7DC)
Substituting values:
![Q=\frac{1}{\frac{1}{4100}+\frac{1}{3390.7278} } =1855.8923W/m^{2} C](https://tex.z-dn.net/?f=Q%3D%5Cfrac%7B1%7D%7B%5Cfrac%7B1%7D%7B4100%7D%2B%5Cfrac%7B1%7D%7B3390.7278%7D%20%20%7D%20%3D1855.8923W%2Fm%5E%7B2%7D%20C)
Answer:
True
Explanation:
A semicircular or circular torch movement should be used when depositing weld beads.