Answer
a. $1.8 \times 10^5 N/m^2$
b. $3.5 \times 10^{-6}$
Work Step by Step
a. The stress is $\frac{F}{A}=\frac{(25000 kg)(9.80 m/s^2)}{1.4m^2}=1.8 \times 10^5 N/m^2$
b. The strain is $\frac{stress}{E}=\frac{175000N/m^2}{50\times 10^9 M/m^2}=3.5 \times 10^{-6}$