A circular rod of length 26 cm and diameter 7 mm is made of 1045 grade steel. (a) Calculate the stress (in MPa) and strain in the rod, and its extension (in um), when it is subjected to 8 kN of tension. stress strain extension MPa m (b) At what force (in kN) would the rod begin to yield? KN (c) By what amount (in um) would the rod have to be stretched beyond its original length in order to yield? m