Consider a rectangular fin with a length of $20$ mm $,$ a width of $10$ mm and a thickness of $6$ mm $.$ The ambient surroundings have a temperature of $25$ deg C with a convection coefficient of $75\frac{W}{m^2}K.$ The material is AISI $302$ stainless steel and the temperature of the base is $250$ deg C$.$ Using Figure $3-43($Efficiency of straight fins graph$)$

a$.$ determine the efficiency of the rectangular fin

b$.$ determine the fin heat transfer rate

c$.$ determine the heat transfer from the wall at the base of the fin that would occur if no fin were present

d$.$ determine the effectiveness of the triangular fin

e$.$ is this an effective fin? Why?

Complete all of the above calculations for a triangular fin and compare the result. Solve neatly please. FIGURE $3-43$ Efficiency of straight fins of rectangular, triangular, and parabolic profiles.