A Very Light 1

Multiple Choice

A very light 1.00-m wire consists of two segments of equal length,one of steel (Young's modulus is 2.00 × 10¹¹ N/m²) and one of brass (Young's modulus is 9.0 × 10¹⁰ N/m²) .The steel segment is 1.50 mm in diameter,and the brass segment has twice this diameter.When a weight w is hung from the ceiling by this wire,the steel segment stretches by 1.10 mm.Find the weight w.

A) 190 N
B) 390 N
C) 780 N
D) 1000 N
E) 3100 N