Answer:
strain energy=0.049J
modulus of resilience=49.81N/m^2
Explanation
U=N^2LA/(2E)
U=strain energy
L=leght
A=A rea=(pi/4)D^2
E=young Modulus for steel 200.000N/mm^2
N=tensile load
Solving:
U=(20N/mm^2)(2000mm)(pi/4)(25mm)^2/(2*200.000N/mm^2)=49.087Nmm=0.049J
MODULUS Of RESILIENCE
Ω=U/volume
Volume=2x(pi/4)*(0.025)^2=9.817x10-4m^3
Ω=0.049J/9.817x10-4m^3=49.81N/m^2