only need a for the last question please

The diffusion coefficients for species A in metal B are given at two temperatures: (a) Determine the value of the activation energy Qd( in J/mol). J/mol (b) Determine the value of D0. m2/s (Use scientific notation.) (c) What is the magnitude of D at 1190C ? m2/s (Use scientific notation.) For a bronze alloy, the stress at which plastic deformation begins is 291MPa and the modulus of elasticity is 117 GPa. (a) What is the maximum load that can be applied to a specimen having a cross-sectional area of 304mm2 without plastic deformation? (b) If the original specimen length is 120mm, what is the maximum length to which it may be stretched without causing plastic deformation? (a) N (b) mm