Problem $1-$ Given the force and deflection data for a stress strain test for a cylinder of $11$ inches long and a diameter of $0\mathrm{.}75$ inches determine the following:

D$.$ Determine the toughness of this material.

E$.$ If a stress of $0\mathrm{.}5{}_{yp}$ is applied determine the length of the part while the stress is

applied

F$.$ If a stress of $1\mathrm{.}25{}_{yp}$ is applied determine the length of the part while the stress is

applied and when the stress is removed.