A Brass Rod (E = 110 GPa) with a Cross-Sectional $P_{1}=15 \mathrm{kN}, P_{2}=10 \mathrm{kN} \text {, and } P_{3}=8 \mathrm{kN}$

A brass rod (E = 110 GPa) with a cross-sectional area of 250 mm2 is loaded by forces $P_{1}=15 \mathrm{kN}, P_{2}=10 \mathrm{kN} \text {, and } P_{3}=8 \mathrm{kN}$ . Segment
Lengths of the bar are a = 2.0 m, b = 0.75 m, and c = 1.2 m. The
Change in length of the bar is approximately: (A) $0.9 \mathrm{~mm}$
(B) $1.6 \mathrm{~mm}$
(C) $2.1 \mathrm{~mm}$
(D) $3.4 \mathrm{~mm}$

D