You may have noticed that when you recorded the area under the force vs. distance curve you used units of N·m. When you calculated the change in potential energy (∆U) the units where joules (J). Both are a measure of the work. Is there a problem? Explain. Hint: ""Unit Analysis""

Asolid round steel rod 6.25 mm in diameter and 375 mm long is rigidly bonded to the end of solid square brass rod 25 mm on a side and 300 mm long. the geometric axes of the bare are along the same line. an axial tensile force of 5.4 kn is applied at the extreme ends of the assembly. for steel e = 200 gpa and for brass e = 90 gpa. determine the total elongation for the assembly.