Consider a steel rod of diameter 4.5 mm and length 3.3 m. If a compressive force of 4900 N is applied to each end, what is the change in the length of the rod?
You need to calculate the stress on the rod and compare this with the mechanical properties of the steel. It would help if you were given more info. You will need to know something about the steel such as the yeild stress and E, the modulus of elasticity. The value of E is about the same for a wide range of steels. So long as the applied stress is below the yield stress, the strain is all elastic and is calculated from E. The real answer is that you can not answer this question since you do not know what the temperature is. Given the applied load, the change in length will be much different at room temperature than at 1500C.
