Answer:
surface temperature of the chip located 120 mm Ts=42.5°C
surface temperature of the chip in Mexico Ts=46.9°C
Explanation:
from the energy balance equation we have to:
q=E=30W
from Newton´s law:
Ts=Tα+(q/(h*A)), where A=l^2
N=h/k=0.04*(Vl/V)^0.85*Pr^1/3
data given:
l=0.12 m
v=10 m/s
k=0.0269 W/(m*K)
Pr=0.703
Replacing:
h=0.04*(0.0269/0.12)*(10*0.12)/((16*69x10^-6))^0.85*(0.703^1/3) = 107 W/m^2*K
The surface temperature at sea level is equal to:
Ts=25+(30x10^-3/107*0.004^2)=42.5°C
h=0.04*(0.0269/0.12)*((10*0.12)/(21*81x10^-6))^0.85*(0.705^1/3)=85.32 W/(m*K)
the surface temperature at Mexico City is equal to:
Ts=25+(30x10^-3/85.32*0.004^2)=46.9°C
