A36 structural steel has a yield point of 250 MPa and an ultimate tensile strength of approximately 450 MPa.
(a) What is the maximum mass that you can suspend from a 6.1 cm-diameter, 3.2 m-long A36 steel bar before the bar gets a permanent set?
(b) What is the maximum mass that you can suspend from the same bar such that it does not break?
(c) What diameter of spider silk thread would you need to suspend the same mass without the thread reaching its ultimate tensile strength of 1000 MPa? (Use the mass you calculated in part (b).)