Answer:
Ts = 413.66 K
Explanation:
given data
temperature = 20°C
velocity = 10 m/s
diameter = 5 mm
surface emissivity = 0.95
surrounding temperature = 20°C
heat flux dissipated = 17000 W/m²
to find out
surface temperature
solution
we know that here properties of air at 70°C
k = 0.02881 W/m.K
v = 1.995 ×
m²/s
Pr = 0.7177
we find here reynolds no for air flow that is
Re = 
Re = 
Re = 2506
now we use churchill and bernstein relation for nusselt no
Nu = 
= 0.3 + ![\frac{0.62 Re6{0.5}Pr^{0.33}}{[1+(0.4/Pr)^{2/3}]^{1/4}} [1+ (\frac{2506}{282000})^{5/8}]^{4/5}](https://tex.z-dn.net/?f=%5Cfrac%7B0.62%20Re6%7B0.5%7DPr%5E%7B0.33%7D%7D%7B%5B1%2B%280.4%2FPr%29%5E%7B2%2F3%7D%5D%5E%7B1%2F4%7D%7D%20%5B1%2B%20%28%5Cfrac%7B2506%7D%7B282000%7D%29%5E%7B5%2F8%7D%5D%5E%7B4%2F5%7D)
h = 
0.3 + ![\frac{0.62*2506{0.5}0.7177^{0.33}}{[1+(0.4/0.7177)^{2/3}]^{1/4}} [1+ (\frac{2506}{282000})^{5/8}]^{4/5}](https://tex.z-dn.net/?f=%5Cfrac%7B0.62%2A2506%7B0.5%7D0.7177%5E%7B0.33%7D%7D%7B%5B1%2B%280.4%2F0.7177%29%5E%7B2%2F3%7D%5D%5E%7B1%2F4%7D%7D%20%5B1%2B%20%28%5Cfrac%7B2506%7D%7B282000%7D%29%5E%7B5%2F8%7D%5D%5E%7B4%2F5%7D)
h = 148.3 W/m².K
so
q conv = h∈(Ts- T∞ )
17000 = 148.3 ( 0.95) ( Ts - (20 + 273 ))
Ts = 413.66 K
Answer:
The initial temperature is 649 K (376 °C).
The final pressure is 0.965 MPa
Explanation:
From the ideal gas equation
PV = nRT
P is the initial pressure of water = 2 MPa = 2×10^6 Pa
V is intial volume = 150 L = 150/1000 = 0.15 m^3
n is the number of moles of water in the container = mass/MW = 1000 g/18 g/mol = 55.6 mol
R is gas constant = 8.314 m^3.Pa/mol.K
T (initial temperature) = PV/nR = (2×10^6 × 0.15)/(55.6 × 8.314) = 649 K = 649 - 273 = 376 °C
From pressure law,
P1/T1 = P2/T2
P2 (final pressure) = P1T2/T1
T2 (final temperature) = 40 °C = 40 + 273 = 313 K
P1 (initial pressure) = 2 MPa
T1 (initial temperature) = 649 K
P2 = 2 × 313/649 = 0.965 MPa
Answer:
hmm i would try calling him. ask your mom or other adults where he is!
Explanation:
hope you get help soon!
Answer:
I hot u
Explanation:
it makes things function better and more fluently than a manual version of the certain object
BOY IS IN THE HOOD BOY IS IN THE HOOD
