A 10-Meter-Long Steel Rod (Young's Modulus Of $2 \times 10 ^ { 11 }$

Multiple Choice

A 10-meter-long steel rod (Young's modulus of $2 \times 10 ^ { 11 }$ Pa) having a 0.8-cm radius is supporting a 500-kg mass. The change in the length of the rod is

A) 2.3 mm.
B) 4.5 mm.
C) 1.2 mm.
D) 0.5 mm.