A steel tube is 7 m long and is 6 cm OD with a wall thickness of 4 mm. It hangs vertically with a load of 400 kg attached to its lower end. If the modulus of elasticity is 210 x 106 kPa, find the stress induced in pipe material.
A. 1.39 MPa
B. 1.47 MPa
C. 3.47 MPa
D. 5.57 MPa
E. 12.49 MPa
Answer: D