(a) from the following data of yield strength versus (grain diameter)–1/2 for a cuzn alloy, determine values for the constants σ0 and ky in hall-petch equation. d-1/2 (mm)-1/2 σy (mpa) 4 75 12 175
(b) now predict the yield strength of this alloy when the average grain diameter is 1.0 × 10-3 mm.

Avehicle has an oil leak that is causing the entire oil pan to be wet, but inspection reveals no exact source after cleaning off the oil residue. technician a says to install a fluorescent dye in the crankcase and operate the engine, then re-inspect for leaks with a special light (black light). technician b says the oil leak may be coming from a source at the top of the engine, such as a valve cover gasket. who is correct?

Work out sian speed for the first 30 minutes of her journey. give your answer in km/h.

The sun’s mass is 2.0×10^ 30 kg, its radius is 7.0×10 5 km, and it has a rotational period of approximately 28 days. if the sun should collapse into a white dwarf of radius 3.5×10 3 km, what would its period be if no mass were ejected and a sphere of uniform density can model the sun both before and after?