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:
Due to differences in the nature of the adhesive force and cohesive forces in the molecules of the individual substances and the glass tube.
Explanation:
To understand why this is so, a deep understanding of adhesive and cohesive force is required.
First, what is adhesive force?
Note: Adhesive and cohesive forces are best discussed under macroscopic level.
Adhesive force is the Intermolecular forces that exist between atoms of different molecules e g the forces explain when unlike charges stick together.
Cohesive force on the other hand is the Intermolecular force that exist between atoms of the same molecules e.g the force between hydrogen bonding.
Hence to explain the case scenario above, the adhesive force between the water molecules and the glass molecules is higher than the cohesive force between the water molecules. Hence the high rise.
For the case of the Hexane, the cohesive forces between the molecules hexane is far greater then the adhesive force between the glass molecules and the hexane molecules.
Someone dropped a gallon of milk and you parked over it
Answer:
What subject is this in?? That would help a lot knowing
Explanation:
