SpaceX Mechanical Engineer interview questions

Describe the design differences found in making a stiff structure and a structure where the primary design goal is strength

Interview with the manager 1) For a beam that is attached to the wall on the two end where would you expect the failure mode to occur? 2) what if you had rollers instead being fixed to the wall, would the failure mode change? 3) what are the three modes of heat transfer? 4) Which of the three heat transfer is the most effective? 5) can you describe an application where radiation would be the most effective? 6) how are beams manufactured? 7) if you had a bolt you had to set the torque spec for what information would you need? 8) what is the relation between stress and strain? 9) can you describe the behavior of stress vs strain?