Questions 1 through 4 pertain to either a 2024-T4 aluminum alloy used for lightweight automobile components or a 130B titanium alloy used in nuclear attack submarines. The S-N endurance data

(50percent survival) for the two alloys is shown below. The tensile strengths are 70,000 psi and 155,000 psir aluminum and titanium, respectively. What is the fatigue strength for the 2024-T4 aluminum alloy used for lightweight auto components?If subjected to a cyclic stress featuring a mean stress of 15 ksi, what is the maximum allowable stress amplitude if 50 percent of all material specimens are to survive 10* cycles? Note: outs=70 ksi