10.5 (a) assume for the solidification of iron (problem 10.d1) that nucleation is homogeneous, and the number of stable nuclei is 106 nuclei per cubic meter. calculate the critical radius and the number of stable nuclei that exist at the following degrees of supercooling: 200 k and 300 k.

Coiled springs ought to be very strong and stiff. si3n4 is a strong, stiff material. would you select this material for a spring? explain.

Aplate clutch has a single pair of mating friction surfaces 250-mm od by 175-mm id. the mean value of the coefficient of friction is 0.30, and the actuating force is 4 kn. a) find the maximum pressure and the torque capacity using the uniform-wear model. b) find the maximum pressure and the torque capacity using the uniform-pressure model.

What is the heat treatment of metals? what is the benefit of it? why and how it's useful? answer in details, do not write by hand.