an aluminum rod needs to withstand an applied force of 45,000 pounds. the engineering stress-strain curve for the aluminum alloy is show below. to ensure safety, the maximum allowable stress is limited to 25,000 psi, which is below the yield strength of aluminum. the rod is 150 in long and must deform elastically no more than 0.25 in when the force is applied. what is the minimum diameter (in inches) of the rod with a round cross section?