A brass rod with a length of 1.40 m and a cross-sectional area of 2.00 cm2 is

Question:

A brass rod with a length of 1.40 m and a cross-sectional area of 2.00 cm2 is fastened end to end to a nickel rod with length L and cross-sectional area 1.00 cm2. The compound rod is subjected to equal and opposite pulls of magnitude 4.00 X 10 N at its ends.
(a) Find the length L of the nickel rod if the elongations of the two rods are equal.
(b) What is the stress in each rod?
(c) What is the strain in each rod?