Answer:

Explanation:
Given that;
Thermal diffusivity 
Thermal conductivity 
Heat transfer coefficient h = ( we are to assume the imposed surface temperature ) = 20 W/m².K
Initial temperature = 150 ° C = (150+273) K = 423 K
Then coolant temperature with which the casting is exposed to = 20° C = (20+273)K = 293 K
Time = 40 seconds
Length = 20mm = 0.02 m
The objective is to determine the temperature at the surface at a depth of 20 mm after 40 seconds.


Bi == 0.02



For a wall at 0.2 Bi


Therefore;











Answer:
Chemical Engineers determine how to transport chemicals:
TRUE
Answer:
Please find the answer in the explanation
Explanation:
An employee of a communications company under the jurisdiction of the Public Utilities Commission when prepáring plans for communication lines can be exempted from the licensing provisions of the Professional Engineers Act.
Being an employee of a communications company under the jurisdiction of the Public Utilities Commission is not a criterion for getting a license to be a professional engineer nor a prerequisite for getting the license to be a professional engineer