At approximately what temperature (in Kelvin) would a specimen of an alloy have to be carburized for 1.2 h to produce the same diffusion result as at 750°C for 13 h? Assume that values for D0 and Qd are 3.4 × 10-5 m2/s and 156 kJ/mol, respectively.

The higher the astm grain-size number, the coarser the grain is. a)-true b)-false

Asolid cylinder is concentric with a straight pipe. the cylinder is 0.5 m long and has an outside diameter of 8 cm. the pipe has an inside diameter of 8.5 cm. the annulus between the cylinder ad the pipe contains stationary oil. the oil has a specific gravity of 0.92 and a kinematic viscosity of 5.57 x 10-4 m2/s. most nearly, what is the force needed to move the cylinder along the pipe at a constant velocity of 1 m/s?

Modern high speed trains do not have perpendicular expansion gaps where rails are joined end-to-end any more they are mostly welded together but what might happen if there was a spell of particularly hot weather that causes inspection of the tracks?