One end of a steel rod of radius R = 9.5mm and length L = 81cm is held in a vise (钳子) . A force of magnitude F = 62kN is then applied perpendicularly to the end face (uniformly across the area) at the other end, pulled directly away from the vise. What are the stress on the rod, the elongation Δ L and the strain of the rod? The Young’s modulus of the steel is E = 200x10 9 N/m 2 .
A.
stress = 3.2x10 8 N/m 2 , Δ L = 8.9x10 -4 m, strain = 0.11%
B.
stress = 2.2x10 8 N/m 2 , Δ L = 9.9x10 -4 m, strain = 0.11%
C.
stress = 2.2x10 8 N/m 2 , Δ L = 8.9x10 -4 m, strain = 1.11%
D.
stress = 2.2x10 8 N/m 2 , Δ L = 8.9x10 -4 m, strain = 0.11%