The fatigue data for a brass alloy are given as follows: Stress Amplitude (MPa)
170
148
130
114
92
80
74
Cycles to Failure
3.7×10 4
1.0×10 5
3.0×10 5
1.0×10 6
1.0×10 7
1.0×10 8
1.0×10 9
(a) Make an S-N plot (stress amplitude versus logarithm of cycles to failure) using these data.
(b) Determine the fatigue strength at 4×1064×10 6 cycles.
(c) Determine the fatigue life for 120 MPa.

Consider a 1.2 meter high and 2 meter wide glass window whose thickness is 6 mm and thermal conductivity is 0.78 w/m °c. the room temperature is maintained at 24 °c, while the outdoor temperature is -5 °c. the convective heat transfer coefficients on the inner and outer surfaces of the window are 10 w/m2 °c and 25 w/m2 °c respectively. (a) draw the thermal resistance network, etermine the steady rate of heat transfer t e glass window (c) determine the temperature of the inner surface of the window