5. Please answer the following questions related to metal deformation and flow stress. (8') (1) At strain = ɛ, if the average flow stress is equal to 60% of the

instantaneous flow stress (Yf/Yf= 60%), please calculate the work hardening exponent “n?(2) At strain = 1.8 ɛ, calculate the ratio of the average flow stress to the instantaneous flow stress(Y/Y;).(3) The flow stress is a function of both strain and strain rate. When temperature increases, how do working hardening exponent 'n’ and strain rate sensitivity exponent ´m’ change?