Answer:
Q = 424523.22 kw
Explanation:

k = 48.9 W/m - K
c = 0.115 KJ/kg- K


T_∞ = 35 degree celcius
velocity of air stream = 15 m/s
D = 40 cm
L = 200 cm
mass flow rate




solving for h

h = 675.6 kw/m^2K

Q = 675.6*2.513*(285-35)
Q = 424523.22 kw
Answer:
Engineer A results will be more accurate
Explanation:
Analytical method is better than numerical method. Engineer A has used analytical method and therefore his results will be more accurate because he used simplified method. Engineer B has used software to solve the problem related to heat transfer his results will be approximate.
Answer:Counter,
0.799,
1.921
Explanation:
Given data




Since outlet temperature of cold liquid is greater than hot fluid outlet temperature therefore it is counter flow heat exchanger
Equating Heat exchange
![m_hc_{ph}\left [ T_{h_i}-T_{h_o}\right ]=m_cc_{pc}\left [ T_{c_o}-T_{c_i}\right ]](https://tex.z-dn.net/?f=m_hc_%7Bph%7D%5Cleft%20%5B%20T_%7Bh_i%7D-T_%7Bh_o%7D%5Cright%20%5D%3Dm_cc_%7Bpc%7D%5Cleft%20%5B%20T_%7Bc_o%7D-T_%7Bc_i%7D%5Cright%20%5D)
=
we can see that heat capacity of hot fluid is minimum
Also from energy balance

=


NTU=1.921





Explanation:
Population inversion is a process of achieving more electrons in the higher energy state than the lower energy state. In order to achieve population inversion, we need to supply energy to the laser medium. The process of supplying energy to the laser medium is called pumping.